Department of Physics & Astronomy
Annual Report: NSF Award #EPS-1003897
I. Executive Summary 2
II. Detailed Report 3
A. RII participants and participating institutions 3
B. Program/Project Description 4
B. 1. RESEARCH ACCOMPLISHMENTS AND PLANS: 4
B.1.1. Science Driver 1: Electronic and Magnetic Materials 4
B.1.2. Science Driver 2: Materials for Energetic Storage and Generation 8
B.1.3. Science Driver 3: Biomolecular Materials 12
B.2. DIVERSITY AND BROADENING PARTICIPATION, INCLUDING INSTITUTIONAL COLLABORATIONS 14
B.3. WORKFORCE DEVELOPMENT: 15
B.4. CYBERINFRASTRUCTURE: 17
B.5. EXTERNAL ENGAGEMENT: 20
B.6. EVALUATION AND ASSESSMENT: 21
B.7. SUSTAINABILITY AND PROJECT OUTPUTS: 22
B.7.a. Seed Funding and Emerging Areas 22
B.7.b. Human Resources Development 22
B.7.c. Leveraging NSF Programs 22
C. Management Structure: 22
D. Jurisdictional and Other Support: 22
E. Planning Updates: 22
F. Unobligated Funds: 22
G. Progress with Respect to the RII Strategic Plan: 22
H. Jurisdiction Specific Terms and Conditions: 22
I. Reverse Site Visit (RSV) Recommendations: 22
J. Experimental Facilities: 22
K. Publications and Patents: 22
L. Honors and Awards: 22
I. Executive Summary (to be revised by PET)
Introduction. This NSF award has led to the establishment of the Louisiana Alliance for Simulation-Guided Materials Applications (LA-SiGMA), which brings together Louisiana academic institutions to focus on simulation-assisted materials by design in research and in the education of a new generation of Louisiana material scientists. Three “Science Driver” areas have been identified for specific focus: (1) correlated electronic materials, which show promise as new materials for the design of molecular computers, microelectronics, and high-density recording media; (2) energy materials, which show promise as catalysts, advanced materials for the storage and release of hydrogen, and electrochemical cells and capacitors that store and deliver electrical energy; and (3) biomolecular materials, which can provide encapsulation, delivery, and release of therapeutics to specified targets. LA-SiGMA takes advantage of the Louisiana Optical Network Initiative (LONI), the most advanced high performance computing, network, and communication infrastructure among EPSCoR states. Since the principal barrier to simulation-guided design of materials—multiple length and time scales—challenges conventional scientific disciplines, LA-SiGMA combines researchers with specialized expertise at each scale into teams. Teams include applied mathematicians and computer scientists to ensure efficient utilization of forthcoming high performance computers and include experimentalists to test, validate and guide the computational simulations. These collaborations will position Louisiana to compete effectively for a national center of excellence in multiscale materials modeling and simulation.
Vision: Transformative advances in materials science research and education through a sustained multidisciplinary and multi-institutional alliance of researchers.
Mission: to establish a sustained national center of excellence in computational material science by the end of the project period.
Goals:
Science Driver 1: Electronic and Magnetic Materials: Transform the field by extending many-body formalisms and first principles methods to much larger length scales than currently possible.
Science Driver 2: Materials for Energy Storage and Conversion: Develop and apply multi-scale computational tools to study materials for energy generation, storage, and conversion.
Science Driver 3: Biomolecular Materials: Develop, apply, and validate experimentally multi-scale computational tools for the design of novel vehicles for drug delivery and other applications.
Computational Teams: Develop multi-scale formalisms, algorithms, and codes for materials simulations and modeling; leverage existing tools and make optimum use of the next generation computing environments.
Research Efforts. LA-SiGMA consists of three Science Drivers (SD) and a cyberinfrastructure and cybertools team (CTCI) which incorporates three computational teams with membership rich in Science Driver participants. The structure of the CTCI team enables the development of common computational research tools.
Science Driver 1: Electronic and Magnetic Materials. The goals of the Science Driver 1 (SD1) team are to develop and validate methods that enable the study of complex phenomena in correlated electronic and magnetic materials ranging from transition metal oxides to organic magnets. Complex emergent phenomena include properties such as superconductivity, magnetic, charge or orbital ordering, or other phases that one cannot predict even with an exact and complete understanding of the constituent atoms. These phases often compete, making these materials very sensitive to applied fields and perturbations that can lead to new functionalities. As a consequence of their exotic and diverse physical properties, transition metal oxides are considered to be the frontier of research on “emergent research device materials.” To study these systems, the SD1 team is developing mulitscale methods able to treat physics on the different length scales which characterize these orders, non-local density functional theory methods able to treat the strong correlation effects, and methods which combine these two techniques. The SD1 team includes researchers at LATech, LSU, Southern, Tulane, Xavier and UNO, with a high degree of overlap with the CTCI team. Over 30 students and postdocs have been recruited into SD1.
Science Driver 2: Materials for Energy Storage and Generation. The goal of Science Driver 2 (SD2) is to build a molecular level understanding of materials of importance for energy storage and generation. This understanding is important for improving these materials to meet global energy challenges. The work targets electrode materials for supercapacitors and hydrogen storage materials, and is developing molecular models to investigate catalytic process for the formation of biofuels and toxic biproducts from combustion. The team’s computational goals are to bring insight into the described systems by utilizing accurate ab initio methods, while developing the computational methodology to link these insights—which are often on the scale of a few to dozens of atoms—to the macroscopic process being investigated. This requires the development of new force fields that allow for the simulation of 10,000s of atoms that are parameterized by accurate ab initio results. Furthermore, there is a need to link with longer timescales that are outside the purview of atomistic simulations. Hence, the SD2 team is developing a mathematical model that can link the molecular level properties with long scale dynamical variables.
Science Driver 3: Biomolecular Materials. The goals of Science Driver 3 (SD3) team are to develop, apply, and validate experimentally multi-scale computational tools that will enable the design of novel drug delivery vehicles. The barriers to achieving these goals are the complexity associated with modeling systems with atomistic details over length scales on the order of 10–9 to 10–7 m and the lack of sufficiently efficient force fields to enable simulations to reach time scales of 10–6 to 10–3 s is required for meaningful predictions. SD3 is composed of multi-disciplinary teams of scientists at four institutions (Tulane, LSU, UNO, and LA Tech) that combine theoretical/computational scientists with experimentalists to investigate aspects necessary for building predictive models of uni-molecular and multi-molecular vehicles for targeted drug delivery.
Cyberinfrastructure, Cybertools and Computational Teams (CTCI). CTCI is focused on the development of the formalisms, algorithms and codes used in this project needed to efficiently utilize the next generation of supercomputers. A major research goal of CTCI is to collaborate with the computational teams: (1) Next Generation Monte Carlo Codes, (2) Massively Parallel DFT and Force Field Methods, and (3) Large-scale Molecular Dynamics. In addition, CTCI is also working on execution management, data management, visualization and heterogeneous (GPU) computing. CTCI includes members of all of computational and SD teams. CTCI is the glue that holds the three SDs together.
Diversity. The Diversity Advisory Council is coordinating existing and planned efforts to meet the project’s diversity goals. One major accomplishment, for instance, is the establishment of the Supervised Undergraduate Research Experience program, which is restricted to women and underrepresented minorities. Thirty (30) Louisiana students were competitively selected out of 127 applicants to work with faculty mentors at universities around the State, and future competitions are planned.
Workforce Development. The project contributes to workforce development in the State through the creation of a multi-tiered set of educational programs for graduate and postgraduate students who will enter the workforce as well-trained computational materials scientists. Nine graduate level courses have been offered using HD synchronous video since the beginning of the project. Additional programs encourage high school, community college, and undergraduate students to explore computational materials science as a career, including Research Experiences for Teachers summer programs in New Orleans, Baton Rouge, and Ruston, as well as Research Experiences for Undergraduates (REU) programs at six LA-SiGMA universities.
External Engagement. LA-SiGMA maintains a web portal, a Facebook page, and an SVN (a collaborative software and revision system that maintains current and historical versions of files such as source code, web pages, and documentation). Synchronous collaboration tools such as EVO enable inter-institutional collaboration. The LA EPSCoR monthly newsletter continues to highlight the role played by LA EPSCoR in promoting the development of the State’s S&T resources through partnerships involving its universities, industry, and government. The newsletter is distributed to approximately 1,000 individuals, including faculty members, State legislators, and other stakeholders. The Speaking of Science (SoS) speaker’s bureau introduces thousands of K-12 students to the exciting science being undertaken by Louisiana’s best researchers. During this reporting period, 60 presentations were given to over 2,200 students, an audience comprised of 49% females and 38% underrepresented minorities. Two industry/academia collaborative workshops were held, with the goal of fostering interactions between Louisiana’s leading researchers and representatives of Louisiana’s industrial Research & Development community. One focused on the theme of energy and materials science (100 attendees) and the other (60 attendees) centered on Digital Media and Software Development, a rapidly growing industry in Louisiana.
Evaluation and Assessment. Multiple layers of evaluation and assessment is available to LA-SiGMA: An internal Evaluation and Assessment team, an external evaluator, and the External Review Board (ERB). The Office of Educational Innovation and Evaluation (OEIE) of Kansas State University continues to act as the external evaluator for Louisiana's EPSCoR programs. The logic models and strategic plan developed during Year 1 and accepted by the NSF were used to design and implement an on-line data collection portal called the "Online Advancing Science Information System (OASIS)." Launched towards the end of Year 1, OASIS was used extensively for the data collection needed for the Year 2 report. The data collection templates in OASIS were designed specifically to provide the data requested in the NSF templates and also to help the evaluators assess LA-SiGMA's progress in meeting the strategic plan milestones and outcomes.
Sustainability. A host of initiatives for improving the State’s research infrastructure and enhancing sustainability are administered by the LA EPSCoR office. These programs include: Pilot Funding for New Research ; Links with Industry, Research Centers and National Labs ; Opportunities for Partnerships with Industry ; Preliminary Planning Grants for Major Initiatives ; Travel Grants for Emerging Faculty ; Grantwriting Workshops ; the LA Genius Faculty Expertise Database ; and the SBIR/STTR Phase Zero program. All of these programs have a significant impact on propelling Louisiana’s S&T enterprise to become more competitive and sustainable. LA-SiGMA is actively focused on development of structures that will sustain it well beyond the end of the funding. LA-SiGMA members have led the effort to obtain a DOE Predictive Theory and Modelling Center which would bring the development of NWChem to the state and establish a significant collaboration with Pacific Northwest National Lab. We hosted an NWChem training workshop attended by 32 students. We have taught and are developing graduate level courses to train the current and future generation of computational materials scientists. LA-SiGMA is leveraging its funding and equipment purchases to obtain additional funding and equipment based on our successes. LA-SiGMA is developing new national and international collaborations.
Management Structure. Dr. Michael Khonsari is the Project Director (PD), and Mr. Jim Gershey is Project Administrator (PA). The PD ensures that the various stakeholders operate as a cohesive research enterprise progressing towards realization of project goals and objectives. A 21-member EPSCoR Committee meets at least twice a year. Assisting Dr. Khonsari and the EPSCoR Committee is a professional staff of five full-time individuals whose responsibilities include program management, fiscal and contract management, database administration, coordination of statewide outreach, and communications. The Project Execution Team (PET) oversees the day-to-day activities of the LA-SiGMA project and provides direction and guidance to project participants in each of the science driver and computational teams. The management structure features several interconnected teams designed to effectively implement and assess the project goals, promote project-wide participation in leadership, and ensure effective communications. These teams include the following: Science & Cyberinfrastructure Team; External Engagement & Workforce Development Team; Evaluation & Assessment Team; Industrial Liaison Team (ILT); and Diversity Advisory Council (DAC). An External Review Board (ERB), consisting of a diverse group of eminent scholars, conducts comprehensive programmatic reviews and forwards objective guidance, feedback, and recommendations to the PD and PET, to ensure that program goals and objectives are being met. Biannual “all-hands” face-to-face meetings are used for coordination and identification of new collaborations. The DAC and ILT participate in the biannual all-hands meetings. The ERB attends at least one of these biannual meetings to evaluate all aspects of the project.
Key Accomplishments. Intellectual Merit: New technologies often depend on designing new materials for specific tasks. Examples include materials for computer memories, batteries, and controlled drug delivery. When developing new materials, scientists and engineers search through a vast range of possibilities including complicated mixtures of ingredients, or architectural organizations of materials that present themselves in structures of different sizes and shapes. For example, a material for controlled drug delivery may have to be porous enough to absorb a drug but have a coating that protects the contents until the release environment is encountered. Design of useful, cost effective, and environmentally friendly new materials is a grand challenge for materials scientists. This challenge requires understanding, modeling, and exploiting the complexity of materials on numerous levels, from the small scale of minute constituents to the grand scale of technological applications. The interplay of behavior on multiple time and length scales (i.e., multiscale behavior) can lead to unexpected complex emergent phenomena. Such problems are generally unsolved in materials science.
Modern methods of experimental science and engineering heighten the design challenge by offering the ability to produce designed materials and to test detailed design features, though testing all possibilities is usually not economically feasible. Paralleling this expansion of experimental methods has been an explosion in the power of modern computers, and the evolution of the sophisticated computational science algorithms for simulation of materials, particularly specialized algorithms that take advantage of the hardware advances. The combined progress suggests the goal of simulation-assisted materials by design. This goal has been widely appreciated, and steady progress continues, but transformative progress will require a confluence of experimental and computational facilities together with directed intellectual collaboration. This RII research project builds upon existing state and federal investments in experimental and computational facilities in Louisiana.
Broader Impact : LA-SiGMA is effecting a transformative and sustainable change in computational materials research, education, and applications throughout the State of Louisiana and making the State competitive for a federally funded research center. LA-SiGMA is pushing the scientific frontiers in computational materials science, and enabling Louisiana researchers to use the next generation of heterogeneous, multicore and hyperparallel cyberinfrastructure effectively. LA-SiGMA is building statewide interdisciplinary research collaborations involving computational scientists, computer scientists and engineers, applied mathematicians, theorists and experimentalists. Most significantly, the project will build an inter-institutional computational materials science graduate program that will be unique in its statewide reach and impact, and may be the only one of its kind in the nation.
SD1: Research highlights include a partnership with CTCI to develop massively parallel GPU enhanced codes. These codes employ the state's GPU supercomputers to enable new discovery, and are also ready for use on BlueWaters. John Perdew and his collaborators are developing greatly improved semilocal and nonlocal density functionals that will be employed in electronic structure calculations for molecular magnets and other complex materials of interest to the SD1 science driver team. Experiments are used to both validate our methods and to suggest new materials for study. They are being performed on a wide spectrum of materials, ranging from iron-based high temperature superconductors to organic magnets. SD1 researchers have led the way in teaching three semester-long distance learning courses open to all LA-SiGMA participants, as well as numerous researchers in Europe and North America, teaching methods directly relevant to the research being done in SD1 and CTCI. Our efforts are coordinated through bi-weekly meetings of SD1 and of the GPU team in which SD1 is heavily involved.
SD2: One of the stated milestones is to develop algorithms that combine chemistry and physics of energy storage. During the second year, the SD2 team has carried out calculations to understand how charge is carried and distributed in the electrochemical double-layer capacitors, which are potential components for supercapacitors. Simulations have also been performed to understand how the addition of impurities to a sodium magnesium hydride can increase its ability to store hydrogen, and investigated how adding impurities to C60 influence its thermoelectric properties. The team has carried out DFT calculations to extract appropriate force field parameters to study catalysis. Furthermore, the team has moved into an exciting new area of Lithium-ion battery research, which combines experimental real time imaging combined with DFT calculations. The team’s efforts are coordinated via monthly synchronous meetings using the EVO collaboration tool and strong collaborations with the force field methods and Monte Carlo computational teams with CTCI. SD2 team offered two semester-long distance learning courses during Year 2.
SD3: The goals of the Science Driver 3 (SD3) team are to develop, apply, and experimentally validate multi-scale computational tools to enable the design of novel unimolecular and self-assembled drug delivery vehicles. The barriers to achieving these goals are the complexity associated with modeling systems with molecular detail from nm to μm in size and up to μs or ms in time required to make meaningful predictions. SD3 is composed of multi-disciplinary teams of scientists at five institutions (Tulane, LSU, LSU-Ag, UNO, and LA Tech), combining theoretical/computational scientists with experimentalists to build predictive targeted drug delivery models. Over the first year, a solid foundation was laid recruiting graduate and post-doctoral scholars who developed models and performed preliminary studies to map out interesting systems to explore. In year two, studies have advanced to examine delivery vehicle shapes, conformations, and free energies in depth, as well as to synthesize new vehicles to determine delivery efficacy. SD3 efforts are coordinated locally through weekly meetings and across campuses monthly via synchronous video.
CTCI: In collaboration with SD1, SD2 and SD3, CTCI is developing new techniques (compilation and runtime) for the effective execution of codes on GPUs (Graphics Processing Units), which have become an integral part of next-generation heterogeneous architectures. In collaboration with SD1, CTCI has developed the world's second fastest simulation of spin-glass models. Unlike our main competitor, our codes run on GPU supercomputers like those now being constructed by the NSF. In collaboration with SD1, we have attracted resources to purchase a 400TFLOP GPU supercomputer. In collaboration with all the SDs, CTCI is focused on new force-field development and analysis of data from simulations. In order to foster close collaboration between the SDs and CTCI, six graduate students have been placed on shared appointments with the SDs and have PhD advisory committees consisting of members from CTCI as well as the SDs. Our efforts are coordinated through weekly joint meetings with the SDs. Five CTCI researchers have led the way in teaching semester-long courses in high-performance computing, computational science and compiler optimizations, and are participating in the Beowulf boot camp for Louisiana high school students and teachers.
Actions Taken in Response to Recommendations
II. Detailed Report
A. RII participants and participating institutions
See FastLane and Template A.
B. Program/Project Description
B. 1. RESEARCH ACCOMPLISHMENTS AND PLANS:
B.1.1. Science Driver 1: Electronic and Magnetic Materials
[M. Jarrell, J. DiTusa (LSU), J. Moreno (LSU), and J. Perdew (Tulane)]
Program/Project Description. Strongly correlated materials are characterized by strong interactions between the electrons and ions, which yield, e.g., moment formation and the emergence of complex competing phases. They will serve as a new generation of materials for devices and electronics. The goal of SD1 is to develop and test new computational formalisms, algorithms and codes which will eventually enable the search for new correlated materials on the supercomputer.
Methods Developed/Employed. Investigators using the present generation of Density Functional Theory (DFT) and many body tools, including Dynamical Mean Field Theory (DMFT) and its cluster extensions, have made remarkable progress towards understanding these systems. Nevertheless, DMFT methods scale exponentially in the size of system treated explicitly, and DFT fails to describe strong correlation effect. We are developing and testing multiscale methods that circumvent this exponential scaling and more accurate DFT potentials.
Goals and Milestones for year two include the development and porting of GPU enabled multiscale codes, hyperGGA functionals, synthesis and study of metalorganics and ferroics, and the development and use of codes which combine DFT and manybody methods to enable first principles study of correlated materials.
Recruiting, Hiring and Project Coordination . In the first year of this project SD1 successfully filled the majority of the graduate student and post-doctoral positions allocated to this driver. In year two, we recruit ? postdocs and ? graduate students.
Research Accomplishments
Focus 1: Multiscale Methods for Strongly Correlated Materials
The computation and theoretical prediction of materials properties must confront the electron-electron interaction. Correlated many-body methods, including Quantum Monte Carlo (QMC) [1], are computationally inefficient for systems of many electrons. One way to deal with this problem is to perform multiscale calculations, where QMC is only used to treat correlations on the shortest length scales, with approximate methods to treat longer length scales. The other and more common way is to use the Kohn-Sham density functional theory (DFT) [2], an orbital-based approach in which the electron exchange-correlation energy is provided by an approximate functional of the electron density. The remaining problems are then to improve the accuracy of the available approximations, to understand long-range correlations including van der Waals interactions, and to deal with the fact that even the exact Kohn-Sham band structure can underestimate the fundamental energy gap of a solid [3].
M. Jarrell and J. Moreno, with C.E. Ekuma, S. Feng, Z. Meng, C. Moore and R. Nelson (LSU), are developing multiscale methods for disordered and interacting systems. They have found that graphics
| |
|Figure 1. The hybridization function Γ is the order |
|parameter for the localization transition. It goes to|
|zero at the critical disorder strength Vc. Above Vc, |
|electrons become localized within the length scale of |
|the cluster. |
processing units (GPU’s) greatly accelerate materials simulations, including simulations of Ising-model glasses [4, 5] and QMC calculations. In collaboration with other researchers in the CTCI team they are developing QMC codes tuned [6, 7] for the next generation of GPU supercomputers. To incorporate nonlocal correlations systematically, they have proposed a Cluster Typical Medium Theory (CTMT) that opens a new avenue to the study of Anderson localization in both model and real materials, unlike the coherent phase approximation [8] and its cluster extensions, including the DCA [9]. The idea is to extend
the Typical Medium Theory [10], which replaces average quantities with typical values, to its cluster version (Fig. 2). They have also shown that size extrapolations of calculated properties over multiple scales can converge much better if three length scales are invoked: the shortest one for explicit correlation, an intermediate one treated perturbatively, and a longest one treated for the first time via mean field correlations [11] (See Fig. 2). Finally, they have used density functional theory to generate a band structure for (Ga,Mn)As and (Ga,Mn)N, then applied a Wannier-based downfolding method [12] to get effective interacting Hamiltonians.
| |
|Figure 2. Convergence of the antiferromagnetic leading |
|eigenvalue in the two-dimensional Hubbard model. The results |
|obtained from the multi-scale approach converge faster than that |
|obtained from the two length scale approach. |
The van der Waals interaction is a weak long-range attraction between two objects due to correlations among their fluctuating multipole moments. It is most important when the objects are not otherwise strongly bonded, as for two biological molecules or nanostructures. The accurate calculation of this interaction via many-electron wavefunctions or DFT is feasible only for a pair of atoms or small molecules. Thus standard intermolecular interactions are often based on an atom pair potential picture. Jianmin Tao, John P. Perdew, and Adrienn Ruzsinszky (Tulane) have shown [13-15] how to evaluate this interaction between two quasispherical objects accurately and efficiently, using just the electron densities and static dipole polarizabilities. They have found that the atom pair potential picture is correct at best for the interaction between two solid spheres, but not when one or both objects are spherical shells (e.g., fullerenes). Other work from the Perdew group [16-20] concerns improvements to semilocal and nonlocal DFT approximations.
Most, previous computations utilizing density functional theory (DFT) potentials reported band gaps that are 20-100% smaller than the corresponding, experimental values. Bagayoko, Zhao, and Williams (BZW) have introduced a computational method that circumvents, with first-principle calculations, the above band gap problem. In this reporting period, Bagayoko (Southern Univ.), Ekuma, and collaborators performed ab-initio, self-consistent calculations of properties of ZnO [21] [65], ScN and YN [22] [66], SrTiO3 [23][67], Ge [24] [68], and InP [25] [69]. These calculations utilized the enhancement of the method based on the work of Ekuma, Franklin (EF) and co-workers. The resulting BZE-EF method led to excellent agreement with experiment of the electronic (including band gaps), optical, transport, structural, and elastic properties of the above materials. Fundamental features of the method include (a) the search and attainment of optimal basis sets that verifiably yield the minima of the occupied energies of the systems under study and (b) the avoidance of over-complete basis set with the utilization of the Rayleigh theorem.
Focus 2: Correlated Organic and Ferroelectric Materials
|[pic] |
|[pic] |
|Figure 3. Current vs. Voltage for Polythiophenes |
|containing an in-chain cobaltabisdicarbollide . a) |
|DFT/Green functions simualtions. b) experiment [3]. |
|1T, 2T, 3T=one, two, and three thiophenes. |
Polythiophenes Containing In-Chain Cobalt Carborane centers: Experimental and computational explorations of cobalt carborane complexes that are covalently linked to polythiophenes were performed to study the electrical conductivity with the inclusion of boron clusters. . J. Garno (LSU) performed atomic force microscopy (AFM) surface studies and conducting probe measurements of charge transport of these novel systems. Simulations of these structures by P. Derosa and N. Ranjitkar (LaTech) employing Gaussian09 determined the spin state of these systems. By using a variety of density functionals in their simulations, they concluded that the ground state system is in a spin singlet. In addition, they calculated the conductivity of these structures using Green’s functions on a density functional theory (DFT) Hamiltonian which compared well to the conducting probe AFM measurements as shown in Fig. 3. Recent conducting probe AFM characterizations by Garno's group indicate that polymers with bithienyl and terthienyl behave like heavily doped semiconductors rather than pure semiconductors, while the current-voltage (I-V) profile for poly-thienyl exhibits no measurable current consistent with the insulating character of the film.
|[pic] |
|Figure 4. Optimized structure of an iron |
|cluster of the spinel-type moiety. |
Magnetic and Multiferroic Materials: S. Whittenburg (UNO) has expanded his micromagnetics code to include ferroelectric materials through the use of a Landau-Devonshire potential and correctly predicted the ferroelectric phase transition temperatures of BaTiO3. In addition, he can model the elastic properties of materials including stress-induced changes to the morphology. Thus, the electric or magnetic field induced stress, and the resulting shape changes, can be calculated and directly compared to the experimental results. G. Caruntu (UNO) has developed a novel experimental methodology for the local measurement of the strain-mediated magneto-elastic coupling in nanocomposite films. Here he employs an AFM tip to monitor the piezoresponse of a perovskite layer caused by the magnetostriction of a ferrite layer [26-30]. L. Malkinski (UNO) has also assisted into the development of new technologies to grow multiwall microtubes of magnetic or magnetic and piezoelectric materials where the magnetic properties have been found to depend on the curvature of the films. Malkinski is also involved in the investigation of thin Fe1-xNix alloy films whose composition varies across its thickness and display unusual hysteresis curves. In addition, he has explored liquid crystal/ferromagnetic nanoparticles composites where the liquid crystal device properties depend on the applied magnetic field.
The understanding and control of the magnetic properties of nano- and microscopic materials is important for a large range of applications from pharmaceuticals to improvements in magnetic storage densities. A. Burin (Tulane) has used ORCA quantum chemistry software [31] (BPW91/LanL2DZ level) to model nanoscopic iron oxide clusters finding a high spin (S=12) ground state (Fig. 4) [32, 33]. He plans on extending these calculations to include relativistic corrections [34] to rule out other, nearly degenerate, high spin states of this molecular magnet. Other calculations include the study of DNA base pair radical cations [35, 36] and the modeling of electronic glasses exposed to electric fields [37]. Related experimental work comes from the team of Kucheryavy, Goloverda, and Kolesnichenko (Xavier) which has produced ultrasmall superparamagnetic iron oxide nanoparticles in a surfactant-free colloidal form with sizes ranging from 4 to 8 nm. This was accomplished by varying the nucleation and growth conditions, and using a sequential growth technique. Since the T1 relaxivity for magnetite and its oxidized form, estimated by NMR, was found to be similar, they concluded that oxidized magnetite would be preferred as a more stable and potentially less toxic MRI contrast agent.
|[pic] |
|Figure 5. Fe1-xCoxSi nanowire device. |
|Successive magnifications of a device |
|designed to measure the electrical |
|conductivity of a single crystalline |
|nano-wire. |
R. Kurtz and P. Sprunger (LSU) investigated the magnetic properties of FeAl where DFT calculations [38-45] predict a ferromagnetic ground state at odds with experiment [46, 47]. However, DFT+U methods find a paramagnetic state when U, the correlation energy, is sufficiently strong [48]. More interestingly, DFT indicates that the bulk terminated and incommensurate FeAl(110) surfaces may exhibit ferromagnetic ordering of the Fe atoms, with moments enhanced compared to the bulk [45]. In addition to magnetometry showing that the bulk is paramagnetic, their synchrotron X-ray magnetic circular dichroism (XMCD) measurements carried out at CAMD indicates no ferromagnetism at either the commensurate FeAl(110) or the surface reconstructed incommensurate FeAl2 surface [49-51].
J. DiTusa (LSU) is investigating transition metal silicides, germanides and gallium compounds to explore their interesting magnetic and electrical transport properties. These materials are interesting and important because they are relatively simply grown, have crystal structures that lack inversion symmetry, and range from good metals, to magnetic semiconductors and small band gap insulators. They have explored bulk crystals and crystalline nanowires demonstrating the accurate control of Co dopants in FeSi at the 0.5% substitution level, the ability to measure the conductance of 20 nm wide nanowires to temperatures below 300 mK (Fig. 5), and the discovery of interesting behavior in the Hall effect of Fe3Ga4.
Focus 3: Superconducting Materials
Iron-based superconductors and related materials. Since their discovery in 2008, iron-based superconductors have generated intense scientific interest since the complex interplay between magnetism and superconductivity in these materials suggests that the attraction needed to form bound electron pairs is provided by spin fluctuations [52-56]. A systematic investigation of transport, magnetic, and superconducting properties of the phase diagram of the chalcogenide material using resistivity, Hall coefficient, magnetic susceptibility, specific heat, and neutron scattering was reported in 2010 [57]. Leonard Spinu (UNO) is completing this picture by measuring the London penetration depth in single crystals at ultra-low temperatures as a function of temperature and Se concentration (25% to 45%). Results were presented at several conferences [58, 59].
The Zhiqiang Mao group has synthesized a new layered iron pnictide CuFeSb [60]. In contrast with other iron pnictides and chalcogenides, this material exhibits a metallic ferromagnetic state with a Curie temperature of 375 K. This finding suggests that a competition between antiferromagnetic and ferromagnetic coupling may exist in iron-based superconductors. It also supports theoretical predictions [61, 62] that the nature of the magnetic coupling within the iron plane depends on the height of the anion plane above the iron plane (~1.8 Å for the Sb plane in CuFeSb vs. ~1.4 in FeAs compounds).
In strongly-correlated materials there is typically a close coupling between structure, charge, and spin, leading to a competition among several phases at low temperature. Structural changes at interfaces can drive changes in material functionality. W. Plummer and V.B. Nascimento are measuring surface structure in complex materials via low energy electron diffraction (LEED) [63]. But the analysis of LEED data is an inverse problem: one must search for the surface structure that yields a given diffraction pattern. They have developed novel LEED codes that use global search algorithms [64] and can also tackle the structural determination of multiple terminated crystallographic surfaces. The codes have been tested successfully for BaTiO3 ultra-thin films [64], and will next be applied to multi-phase (001) surfaces of the BaFe2As2 and Ba(Fe1–xCox)2As2 iron pnictide superconducting materials.
Changes in Research Directions, Future Work:
SD1 has been working with CTCI to employ GPU's to accelerate our calculations, and with the CCT to acquire GPU supercomputing resources nearly three times the power that was originally planned and budgeted. This emphasis on GPU heterogeneous computing has replaced the effort to develop hybrid codes described in the original proposal and strategic plan.
B.1.2. Science Driver 2: Materials for Energetic Storage and Generation
[C. D. Wick and B. Ramachandran (LA Tech)]
Program/Project Description
Efficient and clean generation and storage of energy is a major challenge facing our nation and the world. The major focus of the SD2 research area is to develop a molecular level understanding of different energy storage and generation processes, and the how catalysis works to create fuels and harmful bioproducts from energy generation. We have three major thrusts that have been outlined in the proposed work that include investigations into supercapacitors, hydrogen storage materials, and catalysis. We have supplemented this with a new thrust related to lithium ion batteries, which shows greater potential for future funding opportunities related to battery technology. To address these challenges, we are implementing a multidisciplinary strategy that utilizes a variety of computational methods, mathematical models, and experimental measurements. They are designed to bridge length and time scales that can link electron behavior with macroscopic kinetic and thermodynamic properties.
Methods Developed/Employed
The work makes use of a variety of methodologies, ranging from ab initio electronic structure calculations to force field based molecular simulations to mathematical models. This work is also complemented by experimental measurements to verify any computational predictions made, but also the computational methods complement the experimental measurements to bring molecular level insight into the experiments. There is also a significant portion of this research in method and model development including new mathematical analyses of experimental data, mathematical models to predict macroscopic kinetics, and the paramerization of new molecular models or force fields to scale up the investigation of computational materials. It is important to develop these methodologies/models to bring our computational investigations closer to real world applications by either predicting macroscopic properties or investigating systems that more closely resemble realistic systems in size and timescales. The interdisciplinary manner of this research is focused on bring together a variety of experts to enhance the impact of the proposed research in both scope and viability.
Goals and Milestones
• Recruit, engage, and mentor a gender and ethnically diverse group of students and postdocs. Our success is described in the following section.
• Develop algorithms that combine chemistry and physics of energy storage. Our success is described under Foci 1 and 2.
• Develop new force fields for catalytic processes based on DFT functionals. Our success is described under Focus 3.
Hiring and Recruiting
Dr. Ayorinde Hassan was recruited as a post-doctoral fellow at Louisiana Tech to work on catalytic materials and the new direction to be described below. Dr. Hassan is black, of African origin. Dr. Erica Murray, an African-American female, joined the SD2 team at LA Tech as Research Assistant Professor.
Research Accomplishments
Focus 1: Electrochemical Capacitors and Fuel Cell Electrodes [W. Zhang, G.G. Hoffman, L.R. Pratt, and N. Pesika, K.M. Aritakula and S.W. Rick]:
Carbon nanotubes aligned on metal surfaces (nanotube forests) can have very high capacitance making them attractive materials for supercapacitors [65]. These materials consist of the carbon nanotubes, a solvent, propylene carbonate (PC), and an ion pair. By combining experiment, ab initio, and classical molecular dynamics (MD), we are developing the computational tools necessary to improve the design of capacitor materials, by improving energy densities while retaining good power densities [66]. First we need to verify that our molecular model used for classical MD simulations describes interactions between PC and graphite surfaces. To assess this, we carried out measurements of the contact angle between PC and graphite, which assesses the relative interaction strength between PC and graphite (see Figure 6). We used this comparison to adjust our PC molecular model and its interactions with graphite to bring agreement between simulation and experiment.
Another aspect of importance is to understand how charge is carried and distributed in the electrochemical double-layer capacitors. Using ab initio MD with an 80-carbon atom nanotube and one tetra-methylammonium cation (TMA+), the total electron density, electrostatic potential and electron partial charges were extracted. The charges on the ion (see Figure 7) for nine different configurations varied substantially with the distance from the carbon nanotube, indicating significant charge transfer between the ion and the nanotube. These ab initio results can be used to develop molecular models for classical simulations which include charge transfer, enabling accurate simulations for longer time and larger length scales than can be done at the ab initio level [67].
Focus 2: Thermodynamics and Kinetics in Hydrogen Storage Systems [D. S. Mainardi and W. Dai]
The impact of dopants on the stability, dynamics, electronic structure and dehydrogenation properties of NaMgH3 have been studied using first-principle calculations. This investigation is based on methodology proposed by Dathar et al. [68] and findings by Wang et al. [69]. In this respect, the theoretical investigations shows that higher cohesive energies correlate with higher energies in the doped bulk model as illustrated in Figure 8. The partial doping of NaMgH3 results in stronger covalent bonds between transition elements such as Ti and Mg-H atoms, and a weaker interaction between Mg and H with respect to pristine NaMgH3. Based on our electronic structure analyses, NaMgH3 alloyed with co-dopants such as Ti, V, and Zn provides a viable pathway for destabilizing the bonding nature between Mg and H atoms of the material. Therefore, Gibbs Free-Energy Barrier values for desorption of H2 from transition metal doped NaMgH3 surface models show that hydrogen desorption energies can be reduced. This is in agreement with past experimental studies [70]. This finding prompt the research on the synergistic effect of co-dopants on a core/shell doped nanocluster (Figure 9) to facilitate hydrogen desorption. Preliminary results of theoretical investiga-tions conducted on nanoclusters show a positive correlation between cohesive energy and dehydrogenation energy. Furthermore, in nanocluster models, the dehydrogenation energy is lower than in bulk models, in agreement with previous computational studies [71].
To scale up some of this understanding to macroscopic reactors, we investigated metal-H2 reaction systems, which may become a practical means of storing hydrogen [72, 73]. However, the critical issues for storage materials, such as Mg, La, Li etc, are the amount of hydrogen absorbed/desorbed, thermal stability of the hydride, hydrating/dehydrating kinetics, thermodynamics and thermo-physical properties, crystal structures, surface processes like segregation, carbonization [74]. Efficient conditions to form metal alloys become the main targets. LaNi5 (Lanthanum and Nickel) is the most promising alloy because of its low working temperature and pressure, great number of hydrating/dehydrating cycle capacity and physical chemical characteristics, such as unchanged practical size, phase composition and processing at low temperature. We have developed 2D mathematical models governing the hydrogen absorption/desorption in LaNi5 – H2 cylindrical reactors and numerical schemes. The mathematical model includes the continuity equations for hydrogen and metal, momentum equations for hydrogen, and energy equation for hydrogen and metal, as well as the Neumann and Robin’s boundary conditions. Numerical results including temperature, gas and solid densities, and gas velocity, as well as pressure were obtained (see Figure 10 for an example).
Focus 3: Catalytic Reactions on Metal Oxides
Metal Oxide Clusters and Force Field Development (R. Hall, B. Dellinger, C. Wick, B. Ramachandran): Polychlorinated dibenzo-p-dioxins/furans (PCCD/Fs) are toxic materials that can form on the surface of nanoscale metal oxides present in the environment in hazardous waste incinerators, auto exhaust and cigarette smoke [75]. The factors that facilitate the formation are being studied using a combination of computational methods and experimental measurements. Specifically, the studies demonstrate the reduction of metal particles by the dioxin and furan precursors is a stabilizing factor that leads to enhanced reactivity [76]. We are carrying out ab initio calculations (DFT with hybrid functionals) to determine how the structure of small copper oxides (CunOn) n=1-8 reactions with phenol, ortho-chlorophenol and para-chlorophenol. This study aims to identify the mechanism of their formation with the goal of developing procedures to prevent or hinder the formation reactions. Adsorption of, for example, phenol or a chlorinated phenol to a metal oxide cluster is the first step of the formation of PCDD/Fs [77]. The clusters are “hydroxylated” due to the presence of water in the environment. The reaction product of hydroxylated Cu5O5 with 2-chlorophenol is shown in Figure 11.
While ab initio computational methods are well designed to investigate catalytic behavior of small clusters, most catalytic activity occurs at the surface of nanoparticles or in nanopores, which are larger than can be investigated with traditional ab initio methods. To facilitate the investigation of catalytically active nanoparticles and nanopores, a force field is being developed based on ab initio calculations of small clusters that can be used to investigate material properties for these larger materials. Our recent progress has developed a force field to describe copper oxides and aluminum oxide. Despite making all parameterizations to small clusters (fewer than 100 atoms in all situations), we have developed a model that does a good job of reproducing their bulk crystal structure (see Table 1). We are currently expanding the models to investigate reactive catalysis at the surface of the metal oxides, to allow a truly multi-scale approach to be used to investigate catalysis.
Identification of Catalytic Sites on Nitrogen Doped Carbon Nanotubes as New Catalyst for Hydrogen Fuel Cells (G.L. Zhao and S. Yang): Understanding and identifying the elementary steps of catalytic reaction mechanisms and dynamics of catalyzed transformations have been identified as a grand challenge for catalysis research. We carried out an ab initio investigation of how doping carbon nanotubes (CNTs) with nitrogen affects its ability to catalyze oxygen and hydrogen for fuel cells without the need for expensive precious metals [78-80]. Our results (see Figure 12) show that nitrogen prefers to be at the open-edge of the CNT, and oxygen can adsorb and partially reduce on the carbon-nitrogen complex site [81]. We investigated this further and found that the Pauling site is a catalytic for the reduction of oxygen, and investigated potential pathways for its catalyzed rection with hydrogen to form water. This work is building towards our goal of designing new catalysts through computer-aided simulation for reducing Pt loading in energy technology applications.
Changes in Research Direction, Future Work:
Investigating Lithium Ion Batteries (L. Butler, C. Wick, B. Ramachandran, L. Meda): We are developing new in situ experiments to make real-time observations of the performance of lithium-ion polymer batteries. These are important to investigate the mechanism for electrode degradation, allowing the ability to maximize their lifetimes. Currently, Phase Contrast X-ray Imaging (APS/LSU): Researchers at APS have temporarily built an X-ray interferometer at APS 32-ID to collect data, but its analysis a great challenge. Consultation with an LSU gravity wave physicist led to a new algorithm that reduced computation time from an estimated one-half year to an hour. A second problem has been X-ray optics instability in the test system at APS; more consultation has yielded another new algorithm for unwrapping phase drift errors.
Nanostructured thin films of transition metal oxides such as (RuO2)n have been found to be extremely promising as electrode materials for increasing the energy density of solid-state lithium ion batteries [82]. We are investigating the structure and energetics of (RuO2)n clusters ab initio (DFT) calculations [83], and determining the voltage and structure for the addition and reduction of up to two lithium ions. We have determined how lithium ions affect the structure of the clusters, and are working towards determining the most probable pathways for lithium oxidation and reduction. This work is being complimented by experimental work at Xavier.
B.1.3. Science Driver 3: Biomolecular Materials
[H. Ashbaugh (Tulane) and D. Moldovan (LSU)]
Program/Project Description
SD3 encompasses multi-disciplinary teams of scientists, post-docs, and graduate students from five institutions (Tulane, LSU, LSU-Ag, UNO, and LATech) that combine theoretical/computational scientists with experimentalists working together to develop methodologies for building new predictive models of unimolecular and self-assembled vehicles for targeted drug delivery. The SD3 research projects are conducted under two focus areas: focus 1: Unimolecular delivery vehicles, and focus 2: Self-assembled delivery vehicles.
Methods Employed/Developed
New computational methods are being developed on several fronts within SD3. Specifically, Ashbaugh and Rick are working to port/validate the previously developed Replica Exchange with Dynamical Sampling (REDS) [84] for sampling equilibrium biomolecule conformations in solvent onto LONI. Moldovan and Nikitopoulos are continuing to work with LAMMPS developers at Sandia to link explicit molecular dynamics simulations with commercial CFD solving packages. Mobley has developed a new automated tool for performing high throughput free energy analyses on thousands of systems. Applications of these methods are described below under Research Accomplishments.
Goals and Milestones
The goals of the SD3 team are to develop, apply, and experimentally validate multi-scale computational tools to enable the design of novel unimolecular and self-assembled drug delivery vehicles. To achieve these goals the following milestones were set for the second year: i) Synthesize modular library of core molecules and amphiphilic side chains to explore encapsulation based on architecture and chemistry, ii) Develop new inter-atomic interaction potentials and new coarse-grained force fields for systems containing both biological and non-biological molecules; iii) Develop new hybrid MD/continuum and coarse-grained and accelerated simulation strategies to link length and time scales in biological systems; iv) Synthesize, characterize, and assess new trans-membrane drug delivery systems.
Recruiting, Hiring, and Project Coordination
In the first year, SD3 successfully filled the majority of the graduate student and post-doctoral positions allocated to this driver. In year two, we filled vacant positions, including a new post-doctoral scholar, S. Paraeswaran, and a new graduate student, Janene Baker, both working under S. Rick and D. Mobley at UNO and in collaboration with H. Ashbaugh at Tulane. Additionally in year two, Anne Robinson, was recruited as department chair of Chemical and Biomolecular Engineering at Tulane and joined LA-SiGMA as a faculty member of SD3.
Research Accomplishments
Focus 1: Unimolecular delivery vehicles
Simulation of polymeric drug delivery carriers [H. Ashbaugh (Tulane), L. Liu (Tulane), S. Grayson (Tulane), S. Rick (UNO), and S. Parameswaran (UNO)]: In the Ashbaugh lab a study of the temperature induced collapse transition of poly(n-isopropylacrylamide) in aqueous solution was performed as a potential trigger for drug release from gels. Large-scale simulations were carried out at LONI using replica exchange molecular dynamics, allowing an unprecedented characterization of conformational populations over a broad temperature range. As a result, the thermodynamics of the collapse transition were characterized for the first time via a two-state model, demonstrating the hydrophobic origin of this unusual behavior. This project advances milestones ii and iii.
|[pic] |
|Figure 13. Initial and final molecular dynamics simulation snapshots of linear |
|amphiphilic delivery vehicles in water. Similar conformations are observed for |
|cyclic amphiphilic delivery vehicles. |
The Rick and Ashbaugh groups are presently developing models and strategies for simulating the linear and cyclic amphiphilic polymer delivery vehicles synthesized by Grayson [85]. DFT calculations have been carried out to assign partial charges and preliminary simulations have been performed to examine vehicle conformations in water (Figure 13). Over the next year, simulations will be carried out using the REDS [84] algorithm developed by Rick to more comprehensively sample polymer conformations in polar and non-polar environments. This project advances milestone iii.
Synthesis of new unimolecular drug delivery vehicles: [S. Grayson (Tulane) and Y. Yang (Tulane)]. Research in the Grayson laboratory has shifted towards efficient means of assembling novel amphiphilic polymeric components via efficient “click” couplings [86]. The two conjugation reactions that exhibit the most utility are the copper-catalyzed azide-alkyne coupling, and the thiol-ene reaction. The versatility of this modular approach – the synthesis of individual amphiphilic components and the assembly of multifunctional amphiphilic polymers – requires substantial input from modeling in order to direct synthetic efforts. The modeling efforts of Ashbaugh and Rick (above) provide insight into the most effective means for preparing amphiphilic systems which are likely to assemble into discreet nanometer sized carriers that are of most use as biological delivery vehicles. This project advances milestones i and iv.
Nanoparticle delivery to cancer tissues: [P. DeRosa (LATech)]. Diffusion of nanoparticles in blood vessels and tumors was simulated using a combination of fluid dynamics and Monte Carlo. The model accurately predicts particle delivery to tumors as a function of relevant parameters such us blood pressure, particle size, pore size, interstitial pressure and nanoparticle concentration. This year activities were aligned with Patrick O’Neal’s (LATech) experimental group, and common ground for validating our simulation predictions have been established. This project advances milestones iii and iv.
Focus 2: Self-Assembled delivery vehicles
|[pic] |
|Figure 14. Simulation snapshots of a single span-80 monomer and a |
|self-assembled span-80 bicelle. |
Simulation studies of span-80 assembly [D. Moldovan (LSU), C. Sabliov (LSU-Ag), D. Nikitopoulos (LSU), H. Ashbaugh (Tulane), B. Thakur (LSU), B. Novak (LSU), R. Kumuditha (LSU), J. Lin (LSU), and K. Xia (LSU)]: Span-80 is nonionic surfactant whose assembled structures might be used for drug delivery. Improved potential energy parameters for span-80 were previously developed, leading to simulated densities in agreement with experiment. The self-assembly behavior of span-80 in water was also different with the improved parameters. With the improved parameters, span-80 was found to form curved bicelles (bilayer with closed edges) in water (Figure 14), in difference to the original parameterization that only predicts spherical micelles. This structure is a precursor to vesicles, which have been observed for span-80 [87]. The simulation was terminated after 200 ns, and it was determined that the time and length scales for the self-assembly of span-80 are beyond the capability of atomistic simulations. A periodic span-80 bilayer will therefore be used to study drug molecule interactions as a model for a vesicle patch. This project advances milestones ii and iii.
Hybrid MD-continuum simulation methodology for biomolecular systems: [D. Nikitopoulos (LSU), D. Moldovan (LSU), K. Hesary (LSU), B. Novak (LSU)]. Work has been conducted towards further development of formalisms and computational tools for coupling continuum CFD and MD simulation codes for study of non-equilibrium flow phenomena in mixed-scale domains involving biological materials. Kasra Hesary, working with the group, has successfully used these tools to couple LAMMPS to a commercial continuum code (ANSYS/ Fluent) and verified the results for simple test problems. The hybrid simulation implementation was tested using sudden-start Couette flow in single and two-phase systems, demonstrating the capability of these hybrid tools to yield quantitative predictions in agreement with analytical solutions. Currently we are working with CTCI colleagues to leverage use of CPU/GPU computing to further accelerate these simulations. This project advances milestone iii.
Polymeric nanoparticle-cell interactions [C. Sabliov (LSU-Ag), S. Grayson (Tulane), D. Moldovan (LSU), and R. Devireddy (LSU)]: The entrapment of bioactive compounds in polymeric nanoparticles enhances cellular uptake, drug efficacy, and drug stability. Particle size (1nm - 1μm), surface charge, and hydrophobicity play a vital role in the ability of nanoparticles to be endocytosed by the cell. Poly (lactic-co-glycolic) acid (PLGA) and chitosan-coated PLGA particles (PLGA/Chi) were developed to utilize the mucoadhesive property of chitosan and PLGA’s ability to efficiently entrap hydrophobic and hydrophilic drugs. PLGA and PLGA/Chi NPs loaded with antioxidants were synthesized and characterized. Particles measured 120 nm on average, with 100% entrapment efficiency. TEM clearly indicates PLGA particles aggregate under acidic conditions, while Chi/PLGA particles aggregate near neutral conditions. Loss of the positive charge of Chi/PLGA NPs near the pKa of chitosan (~6.5) adversely affects their mucoadhesive capacity and uptake. To ensure a positive charge of the nanoparticles under neutral physiological conditions, a chemically modified chitosan soluble at basic pH was synthesized and particles was made. The effect of size and charge on NP uptake will be assessed in Caco-2 cells over the next year. This project advances milestone iv.
Strategies for free energy evaluation in biomolecular systems: [D. Mobley (UNO), S. Rick (UNO), J. Baker (UNO), and H. Ashbaugh (Tulane)]. Over the past year an automated method for planning relative free energy calculations has been developed, enabling high throughput free energy estimates for as many as tens of thousands of systems. This work has been presented at national and international meetings, and this tool will be publicly distributed. We also have an ongoing collaboration within SD3 on improving sampling of biomolecular interactions, and are applying a new weighted ensemble technique from collaborators at the University of Pittsburgh to these problems. We continue to work on improving free energy techniques for molecular design in the context of biomolecular interactions, testing these techniques with applications to DNA gyrase and trypsin. This project advances milestone iii.
Changes in research direction, future work:
Anne Robinson’s addition has initiated new research on tau-protein fibrogenesis [88]. In collaboration with Ashbaugh, an REU student has been recruited in the summer of 2012 to explore this direction. This new project is an addition to SD3’s ongoing efforts in drug delivery vehicles.
B.2. DIVERSITY AND BROADENING PARTICIPATION, INCLUDING INSTITUTIONAL COLLABORATIONS
B.2.1. Broadening Participation
Table 1 summarizes the composition of the Alliance for the first two years. We have increased the number of minorities and women in most of the categories. The Diversity Advisory Council (DAC, Strategy 1) met on August 6, 2011 to provide feedback to the EEWD Committee. The DAC suggested that the Industrial Liaison Team needed to add a member from an HBCU. Rachel Cruthirds (from Xavier) has joined. The DAC also suggested that LA-SIGMA faculty advertise to GEM scholars. The
Table 2. Summary of the RII Totals from Appendix B of this and last year report.
|Year Two |Year One |
MaleFem.BlacksHisp.MaleFem.BlacksHisp.Faculty83.6%16.4%8.2%5%87%13%5.6%5.6%Tech. staff66.7%33.3%16.7%16.7%83.3%16.7%33.3%0%Supp. staff18.2%81.8%18.2%9.1%8.3%91.7%16.7%0%Post docs80%12.5%12.5%0%80%20%0%0%Graduates73.2%23.9%11.3%2.8%72.7%27.3%9.1%2.3%Undergrad.57.3%41.2%33.8%2.9%56.9%43.1%36.2%1.7%Leadership87.5%12.5%12.5%0%87.5%12.5%12.5%0%Ad. Boards27.3%72.7%45.4%9%42.9%57.1%28.6%0%EEWD committee drafted a recruitment letter and sent it to the 2012 GEM list. In addition all the postdoctoral, graduate, REU and RET positions has been advertised in the Institute for Broadening Participations (IBP). Two graduate students have been awarded supplemental research assistantships for women and URM students. Funds to supplement department start-up packages (Strategy 3) to recruit new URM and female faculty members have been used at Tulane to recruit Dr. Anne Robinson from the University of Delaware and at LA Tech to recruit Dr. Erica Murray, an African-American female and Research Assistant Professor at IfM. The LA-SiGMA outreach coordinator has contacted the program leaders and collected information for existing 3+2 and 4+1 programs in the state with the goal of creating pipelines (Strategy 4) for students to LA-SiGMA institutions. One student transferred from Xavier to Tulane and joined LA-SiGMA, is majoring in Biomedical Engineering, and will graduate in 2013.
B.2.2 Institutional Collaborations
Within the state of Louisiana, LA-SiGMA participants collaborate with 17 people from seven member institutions, two of these collaborators are from a HCBU institution, and two from industry, the rest are from four academic research institutions. Compared to Y1, we almost doubled the number of collaborators, and we added collaborations from industry.
Ongoing Milestones for Strategic Plan for Year 2:
(1) Hold Annual DAC Meetings-Second Annual Meeting planned for July 23, 2012. (2-3) Reach 30% women and 15% URM graduate students within the Alliance by Y3 – ACTUAL: Year 2: 23.9% female graduate students, 14.1% URM graduate students. (4) Recruit at least 5 students through pipelines described in proposal by end of Year 2 – ACTUAL: 1 student.
B.3. WORKFORCE DEVELOPMENT:
Strategy 1 – Outreach to Middle/High Schools: Open House events have been held at LA Tech/Grambling University and LSU, with 70 and over 1000 students attending, respectively. Tulane plans to hold an Open House in Fall 2012. Dr. Grayson (Tulane) has undergraduate students working with Edna Karr High School (Title I school) to develop a Chemistry AP program. LA-SiGMA partly sponsors the Beowulf Boot Camp at LSU with 37 high school students, four high school teachers, and one community college faculty and student attending. One graduating student from the Louisiana School for Math, Science, and the Arts will participate in the LA Tech REU program, and one high school student is joining the LSU REU program. Ten LA-SiGMA investigators delivered lectures at K-12 schools about research and/or science and engineering throughout the year.
Strategy 2 – Research Experiences for Teachers (RET): For the summer of 2012, five teachers have been selected at LSU's, three at Southern University, three at Tulane, and five at LA Tech/GSU. Of the sixteen teachers, ten are male, two are URM. They teach at a mix of public and private schools, and three of the teachers are faculty members at the Louisiana School for the Math Science and the Arts. The teachers will conduct research in LA-SiGMA faculty members' labs, attend professional development workshops and seminars, and present their research findings at the end of each program. A follow up survey from Year One RET participants was conducted in April 2012.
Strategy 3 – Community Colleges: On October 14, 2011, twenty Community College teachers attended LA Tech short course in Advanced Microscopy Techniques. One instructor and one student from Baton Rouge Community College will attend the Beowulf Boot Camp at LSU and help assess the curriculum from the perspective of community colleges. Two community college students are participating in the REU program-one at LSU and one at SUBR. Two community college faculty members are participating in the RET program as well.
Strategy 4 – Research Experiences for Undergraduates (REU): LA-SiGMA provides six different sites and numerous projects for the REU students. They are recruited using the Institute for Broadening Participation, the XSEDE users’ list and homepage, Shodor webpage, etc. The students work on cutting edge research in material sciences and computational tools and learn how to use the most current cyberinfrastructure tools with individually designed training sessions. In addition, since most LA-SiGMA research groups collaborate with international researchers, REU students are exposed to how international collaborations work. For the summer of 2012, 25 students have been selected (5 at LSU, 5 at LA Tech, 4 at Tulane, 4 at SUBR, 5 at UNO, 2 at Xavier). A follow up survey from Year One REU participants was conducted in April 2012.
Strategy 5 – Graduate Students: Workshops and graduate level courses are broadcast to interested LA-SiGMA institutions using HD synchronous video technology. Two Courses were offered during Fall 2011: Statistical Mechanics (instructor Hall from LSU, broadcast to LA Tech with 20 students attending); and Solid State Physics (instructor Ruzsinsky from Tulane, broadcast to LSU, with 7 students attending). Three courses were offered during Spring 2012: Computational Physics (instructor Moreno from LSU, broadcast to LaTech and Bangalore, India, 24 students); Many-body Theory (instructor Jarrell, broadcast to Bangalore, Zurich and Julich, with 25 attending); 3D+ Visualization (instructor Butler from LSU, broadcast to LA Tech, with 16 students attending). In addition, LA-SiGMA sponsor the participation of its students and postdocs in numerous workshops including the Mardi Gras conference, a Shodor workshop, LONI HPC Parallel Programming Workshop at LSU, the Inaugural LONI HPC User Symposium, the Virtual School of Computational Science and Engineering workshops, and the first in the state NWChem Workshop.
Strategy 6 – Postdocs Professional Development: Cynthia Sisson and Stephanie Aamodt at LSU-Shreveport have developed a best-practice teaching workshop for postdocs and senior level graduate students based on the Michigan State’s FIRST program (Faculty Institute for Reforming Science Teaching). The FIRST program in Michigan is focused on life sciences, so Drs. Sisson and Aamodt are customizing a program for LA-SiGMA; the first workshop will be held in July 2012. Participants will attend remotely via HD video.
Ongoing Milestones from Strategic Plan:
Strategy 1: Increased Attendees at Open House Events-The Open House events had increased attendance over Year One. More than 1,000 people attended the events.
Strategy 2: 20 RET Participants each year- There are 16 RET participants this year. The recruiting strategies will be changed next year to attract a larger number of qualified applicants.
Strategy 3:
Expansion of Short Courses in Year 2- The first Short Course was held at LA Tech in Year One; community college faculty found it very informative, LA-SiGMA plans to hold Short Courses in each area during the Fall of 2012.
Five two-year college participants in Beowulf Bootcamp – The decision was made to assess the course this summer to determine if modifications to the content were needed to better align it with the needs of community college students.
Expansion of 2+2 and other programs by Year 3 – One student recruited to date.
Strategy 4: 30 REU participants each year – 50% will pursue higher education. A follow up survey of 2011 REU participants was conducted in April 2012. The number of participants who indicated they were very likely to pursue at Ph.D. in a Science field increased by 17% after the REU. The number of participants who indicated they were very likely to pursue a career in research or a career in a STEM field increased by 34% and 23%, respectively.
Strategy 5: Five videoconference courses offered with 92 students attending. Incorporation into graduate curricula on two campuses by Y2 – The LA Tech PhD in Molecular Science & Nanotechnology has been approved by the Louisiana Board of Regents, and the Tulane program in Materials Science is also moving forward with local approval. LA-SIGMA faculty and students will participate in these programs through shared courses and research. The LSU/SUBR/UNO Materials Science program has been postponed, but we are hopeful that this initiative can be restarted in the future. However, LSU/SUBR/UNO students and faculty will participate in the programs at Tulane and LA Tech.
Strategy 6: Effective Teaching Workshops scheduled for July 2012 with 22 invited participants.
Eight graduate students and four postdocs at LSU traveled to attend 15 national and international conferences, and three students and one postdoc traveled to universities and national labs to engage on collaborative research. Two of the students had an extended stay at a national lab of at least one month. One student and one postdoc attended a winter school in the US, and will be attending an autumn school abroad.
B.4. CYBERINFRASTRUCTURE:
[J. Ramanujam (LSU) and S. Dua (LA Tech)]
Program/Project Description
The ‘glue’ that holds the three SDs together are the formalisms, algorithms and codes being developed in this project. Therefore, to achieve the goals of this RII project, a cybertools and cyberinfrastructure (CTCI) group of participants, led by Ramanujam at LSU and Dua at LaTech, are working to enable Alliance members to more efficiently utilize the next generation of high-performance computers. CTCI includes members of all of computational and science driver teams, drawn from LA Tech, LSU and Southern. There has been significant interaction between the science drivers and CTCI, including regular meetings with researchers from the science drivers and sharing of students. The coming generation of heterogeneous and multicore machines will present challenges that can only be overcome with the shared experiences of the CTCI teams and applied mathematicians [Lipton and Bourdin (LSU), Dai (LA Tech)], and Li (SU) and experts in high-performance computing [Koppelman, Ramanujam (LSU) and Bishop and Leangsuksun (LA Tech)] and data analytics [Dua (LaTech)].
Methods Employed/Developed
During the second year so far, the CTCI group has focused on the following issues: (a) Development of GPU enabled code [Ramanujam (LSU)]; (b) Development of high-quality codes for parallel tempering and quantum Monte Carlo techniques; (c) Parallel programming tools [Leangsuksun (LA Tech)]; (d) Execution management tools and environment [Bishop (LaTech)]; (e) integration of CFD and MD simulation techniques; and (f) Analysis of MD simulation data [Dua (LA Tech)].
Progress towards Goals and Milestones
A major research goal of CTCI is to collaborate with the computational teams in the development of: (1) Next Generation Monte Carlo Codes, (2) Massively Parallel Density Functional Theory and Force Field Methods, and (3) Large-scale Molecular Dynamics. In order to achieve the proposed goals, the following milestones were set for year 2: (i) development of techniques to achieve good performance on GPUs for Monte Carlo and Parallel Tempering codes; (ii) develop software support for execution management; and, (iii) work on analysis techniques for MD simulation data.
Recruiting, Hiring and Project Coordination
In the second year of the project, CTCI has recruited a new postdoc and a new graduate student to complement the postdoc and the shared graduate students continuing from Year 1. The students are shared between faculty in CTCI and the three SDs. CTCI participants have been engaged in weekly meetings with the science drivers on several aspects including code development and compiler optimizations for GPUs and support for execution management.
Research Accomplishments
Focus 1: Next Generation Monte Carlo Codes:
Monte Carlo (MC) simulations can bypass long time scales by directly calculating free energies associated with activated (long time) processes and by allowing dynamical properties to be studied without following the dynamics serially. CTCI is working with the MC computational team and SD1.
Program Optimizations for GPU Codes [Ramanujam (LSU)]: The emergence of GPUs as cost-effective and powerful processors for general-purpose computing has raised interest in their use for many scientific and engineering applications (e.g., due the availability of the CUDA programming model on NVIDIA GPUs) but further exacerbates the software development challenges. Hence, the automatic transformation of sequential input programs into efficient parallel CUDA programs is of considerable interest. Recently, Ramanujam (LSU) and the students and postdoc have started work on understanding the impact of and interactions among code optimizations for GPUs, in particular, for the Hirsch-Fye QMC and Parallel Tempering codes (described next). Understanding interactions among optimizations is a key step in realizing the potential performance of GPUs. In addition, properly dividing the code segments among the CPU and GPU for execution and providing co-ordination between these are important. For this study, we are using the PLUTO [89] compiler. We will extend the study to use PGI Accelerator.
Tools for GPU programming [Leangsuksun (LaTech)]: In the area of tools for GPU programming, Leangsuksun has collaborated with Alex Safarenko and Sven-Bodo Scholz (Univ. of Hertfordshire, UK) in parallel programming tool development. The project is based on a SAC (Single Assignment C) toolset that enables parallel application developers to express their problems in a high-level language and the toolset is able to generate codes for various target HPC architectures including multicore and GPGPU. The collaborative work will introduce fault tolerance to SAC and its parallel applications.
Development of High-Performance Codes:
Hirch-Fye QMC [Abuasal, Moore, Tam, Thakur, Yun, Ramanujam, Moreno, Jarrell]: One of the first successful applications of QMC was to study the problem of a correlated impurity in an uncorrelated host. The Hirsch-Fye QMC (HFQMC) algorithm was developed for this problem. More recently, together with similar methods such as continuous time QMC (CTQMC), it has gained broader acceptance as the impurity or cluster solver for dynamical mean field theory and its cluster extensions such as the dynamical cluster approximation (DCA). We are developing GPU-accelerated HFQMC code. The GPUs’ sheer number of concurrent parallel computations and large bandwidth to many shared memories take advantage of the inherent parallelism in the Green function update and measurement routines, and can substantially improve the efficiency of the Hirsch-Fye code.
Parallel Tempering [Feng, Fang, Tam, Thakur, Yun, Ramanujam, Moreno, Jarrell]: We develop high-performance GPU versions of the parallel tempering method (also called replica exchange). Parallel tempering is now widely used to improve the efficiency of Monte Carlo calculations. We use parallel tempering [4] together with multi-spin coding [90] to perform GPU simulations of Ising glasses, in addition to a number of code optimizations. We have explored a number of choices such as data layouts, GPU kernel granularities, parallel tempering swap frequency, loop optimizations, etc. The performance of the latest version of the code is around 49ps/spin flip, the second fastest such code in the world; however, unlike our competitors [91, 92], our code runs on GPU machines like those being built for NSF XSEDE.
Focus 2: Massively Parallel Density Functional Theory and Force Field Methods [Wick (LaTech), Rick (UNO)]
The development of new force fields relevant for catalysis and biological simulations has been carried out. It is important to elucidate the role of charge transfer on interfacial properties of liquids and materials. The interfacial region has symmetry breaking, which results in changes in interaction behavior, such as asymmetric hydrogen bonding, and differences in dielectric mediums. Wick (LaTech) and Rick (UNO) added intermolecular charge transfer to a recently developed flexible and polarizable water model [93]. This model was compared with ones recently developed by Lee and Rick [67], which included one with intramolecular charge transfer and one without. The effect of including intermolecular charge transfer is modest on interfacial properties, but it was found that a negative charge at the air-water interface was calculated, but below that of capillary electrophoresis experiments [94]. The work shows that part, but not all, of the observed negative charge at the air-water interface may be explained by intermolecular charge transfer between water molecules.
Focus 3: Large-scale Molecular Dynamics
Workflow management for MD [Bishop (LaTech)]: While MC simulations can study the statistical properties of long time scale processes, simulating the dynamics at the molecular level requires Molecular Dynamics (MD) methods. A significant aspect of running Monte Carlo simulations is workflow management, which also has implications in other areas. Using software tools developed as part of LA-SiGMA (by Bishop at LaTech), we are able to successfully distribute thousands of high-performance simulations across Louisiana Optical Network Initiative (LONI) and XSEDE resources. We completed nearly 4,000 simulations (820,000 SU) in support of the Ascona B-DNA Consortium's efforts to conduct approximately 40 separate 1 microsecond long molecular dynamics simulations of DNA. In total the simulations provide a comprehensive case study of the material properties of DNA as a function of sequence. ManyJobs (which implements the notion of pilot jobs) and its SAGA based cousin BigJob demonstrate how many high performance computing tasks can be efficiently scaled across widely distributed computational resources such as LONI or XSEDE.
Hybrid MD/Continuum Methodologies [Kasra Fattah-Hesary, Moldovan, Nikitopoulos, Pacheco (LSU)]: Kasra Fattah-Hesary, a shared student between CTCI at LSU and the group led by Moldovan and Nikitopoulos, with significant help from Alexander Pacheco (HPC, LSU), has worked on developing new algorithms and codes based on a variational approach and hybrid MD/continuum methodologies, which have been added as modules to the LAMMPS package.
Other Areas
Data Mining: Data Adaptive Classification and Clustering [Dua (LaTech)]: Multi-dimensional data, such as that from MD simulations, is challenging to analyze due to its large volume, complexity and sparseness of the points within the data, which affect both the accuracy and efficiency of supervised learning methods. Data mining techniques such as feature selection and feature extraction are employed to reduce the dimensionality of the data but in these methods, each feature is considered separately and ignores feature dependencies, which can adversely affect the accuracy and efficiency of classification techniques. Our research here is focused on partitioning based rule-based supervised classification, where rules are generated by discovering feature dependencies among discovered partitions of each dimension of the dataset we have developed a data-adaptive rule-based classification system that generates relevant rules by finding adaptive partitions using two unique methods: slope based partitioning and non-slope based partitioning of the data. The adaptive partitions are generated from histogram by analyzing tuple tests such as peak-valley-peak triplet, valley-peak-valley triplet, peak-valley-peak-valley-peak set and valley-peak-valley-peak-valley set. These partitions allow discovering efficient and relevant rules that classify new data correctly. In addition, we have developed a data mining algorithm for data shrinking and clustering multidimensional datasets.
Changes in Research Directions, Future Work
Given the relatively early stage of the project, no major change in research direction was undertaken, in spite of the fact that some of the CTCI faculty originally engaged in parallel software at LSU (Sterling) have moved on from LSU. We have added David Koppelman (ECE, LSU) for GPU software development. We are in the process of finding additional faculty participants for CTCI starting from fall 2012.
B.5. EXTERNAL ENGAGEMENT:
B.5.1. Public Lectures and Events: LA-SiGMA faculty and graduate students from Louisiana State University participated in two Baton Rouge area's NanoDays events (Strategy 1) at BREC's Highland Road Observatory (125 visitors) and the Louisiana Arts and Science Museum (400 guests). LSU LA-SiGMA also participated in Super Science Saturday with over 1,000 people attending. Dr. Bagayoko (SUBR) presented a talk at the AAPT Summer Meeting in Philadelphia, and also at the New Physics Faculty Workshop, APS Headquarters, College Park, MD. LA-SiGMA created a web portal (Strategy 2) for distribution of the project deliverables (). LA-SiGMA has also created a repository and version control system (Strategy 3) for code development and distribution. Dr. Bishop (LA Tech) and Brad Burkman (RET) had been selected by the LittleFe project () to receive mini-supercomputers. The computers are being used in various outreach events and in teaching. Many of LA-SiGMA faculty, students and postdocs participated in the NSF/LA EPSCoR sponsored workshop on Science: Becoming the Messenger.
B.5.2. HD Synchronous Video (Strategy 4): LA-SiGMA is currently in negotiation with vendors to order required HD hardware. The Board of Regents has pledged funds to leverage LA-SiGMA funds and purchase is planned for summer 2012.
B.5.3. Newsletter/Brochures/Highlights (Strategy 5): LA-SiGMA has created a professional brochure, as well as several brochures for specific events, like the REU and RET programs. LA-SiGMA has also created a facebook page to post pictures and update members about events. Highlights have been prepared for distribution to NSF. LA-SiGMA has been mentioned once in the LA EPSCoR newsletter.
B.5.4. Formal Mechanisms (Strategies 6 and 8): An all-hands meeting was held April 2, 2012. A second all-hands meeting has been scheduled on July 23, 2012. The NSF program officer, the External Review Board, the Diversity Advisory Council, and the Industrial Liaison Team will attend the second meeting.
B.5.5. International and National Collaborations (Strategy 7): LA-SiGMA researchers collaborate with 30 people at 27 different institutions in the US. Half of those collaborators come from 14 academic research institutions, eight from five different national laboratories (Argonne, Brookhaven, Lawrence Berkeley, NIST, and Sandia), four from industry (Absorption Systems, Inc., Agilent Nanomeasurements division,Vertex Pharmaceuticals, and Ford Motor Company), two from HBCUs (Howard and Florida A&M Universities), and one from a primarily undergraduate institution (Hillsdale College). At an international level, seven collaborators come from different universities in Germany, India, and Belgium, and two from laboratories abroad (UK and Thailand). Compared to Y1, in Y2 we observed a moderate increase in the number of collaborators, but we saw a sharp increase in the number of institutions. We added another collaborator at the international level.
Milestones for Y2 in External Engagement:
Strategy 1:
Three LA-SiGMA researchers have appeared on TV/radio to discuss their research or science and engineering in general.
At least one public lecture delivered each quarter: LA-SiGMA researchers delivered 15 public lectures this year.
At least one lecture delivered to industrial audiences each quarter: Four LA-SiGMA investigators delivered lectures to industrial audiences this year.
Strategy 2: Web traffic increases 20% annually- In the period of January 1, 2012 to June 6, 2012, the LA-SiGMA webpage received 1,564 visits, 64% of those were new visitors, 38% of the visitors were from Baton Rouge, 10% from New Orleans, and 8% from Ruston, Louisiana. At the moment we don't have another period to which we can compare these statistics, but we will be able to compare statistics starting Y2.
Strategy 3: SVN maintained and upgraded in Y2-5; 100 code downloads per year starting Y3. The software page received 72 visits, with about 70% of new visitors. Twelve different people clicked on the links that take them to the software page of ManyJobs and BigJob where they can download the software.
Strategy 4: Spending freezes and change in IT personnel have delayed the purchase of the equipment.
Strategy 5:
At least two LASiGMA highlights featured in LA EPSCoR newsletter each year. Only one newsletter featured a LA-SiGMA researcher John Perdew. The newsletter wasn’t published for several months because the EPSCoR office didn’t have a PR person.
At least one story picked up by regional/national press: Nanodays was picked. Four LA-SiGMA investigators indicated that a story about his or her LA-SiGMA work was picked up by the national or regional press.
Strategy 6: Regular interactions with NSF, at least three research highlights reported to NSF annually: Eight research highlights were submitted to NSF. Two images from Bishop (LA Tech) were featured on the NSF Multimedia Gallery ().
Strategy 7: At least one LA-SiGMA faculty and at least one student will visit and work in an international lab for one or more weeks each year. Nine LA-SiGMA faculty and seven LA-SiGMA students visited and worked in international labs.
Strategy 8: Full participation in biannual meetings. Ninety-three LA-SiGMA participants attended the April 2012 meeting.
B.6. EVALUATION AND ASSESSMENT:
B.7. SUSTAINABILITY AND PROJECT OUTPUTS:
B.7.a. Seed Funding and Emerging Areas
B.7.b. Human Resources Development
B.7.c. Leveraging NSF Programs
As reported in Appedix E (Project Outputs), during the current reporting period, LA-SiGMA senior investigators submitted 96 proposals requesting a total of $130.5 M, and received funding for 33 proposals with a total revenue of $38.5 M, and have 42 proposals with $82.8 M requested currently under review. This is a significant improvement over the previous reporting period (Year 1) when we reported 15 proposals submitted (total request $7.9 M), 2 funded ($119K), and 11 under review ($7.7 M).
Also during this reporting period, we report 39 published peer-reviewed papers (compared to 17 in Year 1) 12 of which acknowledge primary support of the RII award and 27 acknowledge partial support.
LA-SiGMA researchers from LSU have established a strong research and funding relationship with researchers at Pacific Northwest National Laboratory, the home of NWChem. NWChem is the only open source computational materials science and chemistry toolkit made generally available, being supported and developed and maintained by a national lab in the US. As part of this collaboration, LA-SiGMA students are invited to intern at the lab, a vigorous research collaboration has developed, and we submitted an invited DOE proposal for a Center for Materials and Chemical Sciences Software Innovation lead by LSU.
C. Management Structure:
D. Jurisdictional and Other Support:
E. Planning Updates:
F. Unobligated Funds:
G. Progress with Respect to the RII Strategic Plan:
H. Jurisdiction Specific Terms and Conditions:
I. Reverse Site Visit (RSV) Recommendations:
J. Experimental Facilities:
K. Publications and Patents:
L. Honors and Awards:
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-----------------------
|[pic] |Exp. |Predicted |
|[pic] | | |
|Figure 6. | | |
|Experimental | | |
|picture (top) | | |
|and snapshot | | |
|from | | |
|simulation | | |
|(bottom) of | | |
|the contact | | |
|angle of PC | | |
|next to | | |
|graphite. | | |
| | | |
|[pic]Figure 7.| | |
|TMA+ charge | | |
|for different | | |
|orientations | | |
|next to a | | |
|carbon | | |
|nanotube. | | |
| | | |
|[pic]Figure 8.| | |
|Relative | | |
|cohesive | | |
|energy values | | |
|in doped bulk | | |
|model. | | |
| | | |
|[pic]Figure 9.| | |
|Nanocluster | | |
|model, where X| | |
|is transition | | |
|metal dopant. | | |
| | | |
|[pic][pic] | | |
|Figure 10. | | |
|Cross section | | |
|of a | | |
|cylindrical | | |
|LaNi5-H2 | | |
|reactor (left)| | |
|and of a | | |
|countour of | | |
|hydrogen | | |
|density | | |
|distribution | | |
|alonof a | | |
|countour of | | |
|hydrogen | | |
|density | | |
|distribution | | |
|along the | | |
|reactor after | | |
|60 minutes. | | |
| | | |
|Table 1. | | |
|Experimental | | |
|and Forcefield| | |
|Predictions | | |
|for CuO | | |
|Property | | |
|α |90° |90.3° |
| β |99.6° |96.9° |
| γ |90° |91.0° |
|a(Å) |4.68 |4.56 |
|b(Å) |3.42 |3.55 |
|c(Å) |5.13 |5.03 |
[pic]Figure 11. Copper oxide nanoparticle bound with dioxin/furan precursor.
[pic]
Figure 12. Snapshot of possible early CNT-catalytic pathway for H2+O2.
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