TheAlloy-TheoreticAutomatedToolkit(ATAT):AUserGuide - Brown University

The Alloy-Theoretic Automated Toolkit (ATAT): A User Guide

Axel van de Walle

December 6, 2023

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Chapter 1

Features/Capabilities

The Alloy-Theoretic Automated Toolkit (ATAT) is a generic name that refers to a collection of alloy theory tools:

? Codes to construct cluster expansions from first-principles (maps and mmaps). A cluster expansion is a very

compact and efficient expression giving the energy of an substitutional alloy as a function of its configuration

(i.e. which type of atom sits where on the lattice).

? Codes to perform Monte Carlo simulation (emc2 and memc2) of lattice models in order to compute thermodynamic properties of alloys, starting from a cluster expansion.

? Codes to perform lattice dynamics calculations (fitfc, fitsvsl, svsl)

? Codes to calculate electronic and magnetic free energy contributions (felec, fmag, fempmag) using simple

physical or semiempirical models.

? Utilities to combine all of the above to generate free energies that include configurational, vibrational and

electronic contributions (mkteci).

? Codes to generate Special Quasirandom Structures (SQS), to model disordered solid solutions (mcsqs, gensqs)

and to enumerate structures (genstr).

? A large library of pre-computed SQS and structure prototypes.

? Extension of the two above tools that allow the construction of so-called reciprocal-space cluster expansion,

which are useful to model the energetics of alloys exhibiting a large atomic size mismatch.

? Tensorial cluster expansions (gce).

? Elastic constant calculations (calcelas).

? Structure conversion utilities (subcells, supercells, coordinate system changes, file format, etc.) (cellcvrt,

wycked, etc.)

? Scripts to automate tasks (foreachfile, sspp, getvalue, getlines, etc.).

? Codes to generate CALPHAD databases (sqs2tdb).

? Utilities to interface the above tools with first-principles codes, such as VASP (runstruct vasp, runstruct abinit,

runstruct gulp, etc.).

? Job control utilities that enable the efficient use of a cluster of workstations to run the first-principles codes

that provide the input to the above codes (pollmach).

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CHAPTER 1. FEATURES/CAPABILITIES

Chapter 2

Credits and Licence

The Alloy-Theoretic Automated Toolkit (ATAT)1 is a generic name that refers to a collection of alloy theory tools

developped by Axel van de Walle2 , in collaboration with various research groups.

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Collaborators and Credits

The MAPS3 (MIT Ab-initio Phase Stability) code, which automatically constructs a cluster expansion from the

result of first-principles calculations, was developped by Axel van de Walle in collaboration with Prof. Gerd Ceder¡¯s

group4 from the Department of Materials Science and Engineering at the Massachusetts Institute of Technology.

MAPS consists of the following codes: maps, corrdump, genstr, checkcell, kmesh, cv.

The EMC2 (Easy Monte Carlo Code), which automate the calculation of alloy thermodynamic properties via

Monte Carlo simulations of lattice models, were developped by Axel van de Walle in collaboration with Prof. Mark

Asta¡¯s group5 from the Department of Materials Science and Engineering at Northwestern University. EMC2 consists

of the following codes: emc2, phb.

The CSE (Constituent Strain Extension) to both the MAPS and EMC2 codes, which implement the constituent

strain formalism based on a reciprocal-space cluster expansion, was developped by Axel van de Walle in collaboration

with Alex Zunger¡¯s Solid State Theory Group6 at the National Renewable Energy Laboratory in Golden, Colorado

and in collaboration with Gus Hart7 from the Department of Physics and Astronomy at Northern Arizona University.

CSE conssists of the following files: , , .

Mayeul D¡¯Avezac at NREL has provided all the changes needed for ATAT to compile with g++ versions 4.1 and

later as well as intel¡¯s c++ compiler.

Volker Blum at NREL has contributed to improve the portability of the package by providing a perl version of

the chl utility.

Dongwon Shin at Penn State has converted a large number of common lattices (found at the NRL navy web

site8 ) into the atat format. See directory data/str.

Greg Pomrehn has improved the efficiency of the structure enumeration algorithm and contributed the script

mmapsrep.

Jesper Kristensen has been quite active on the ATAT forum, helping me answer queries. He also maintains some

documentation on his web site9

Ruoshi Sun has also answered many queries on the ATAT forum. He has also contributed the apb code.

Chiraag Nataraj has updated the apb code to allow for any number of species.

Martin Ba?ker has written a simple and useful tutorial for ATAT¡¯s emc2 and phb tools for computing phase

diagrams via Monte Carlo. He has also improved the routine allowing user-specified cluster choices in mmaps.

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