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Reliable First-Principles Alloy Thermodynamics via Truncated Cluster Expansions

Nikolai A. Zarkevich·D. D. Johnson
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Abstract

In alloys cluster expansions (CE) are increasingly used to combine first-principles electronic-structure and Monte Carlo methods to predict thermodynamic properties. As a basis-set expansion in terms of lattice geometrical clusters and effective cluster interactions, the CE is exact if infinite, but is tractable only if truncated. Yet until now a truncation procedure was not well-defined and did not guarantee a reliable truncated CE. We present an optimal truncation procedure for CE basis sets that provides reliable thermodynamics. We then exemplify its importance in Ni$_3$V, where the CE has failed unpredictably, and now show agreement to a range of measured values, predict new low-energy structures, and explain the cause of previous failures.

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Nikolai A. Zarkevich, D. D. Johnson. 2004-04-16. Reliable First-Principles Alloy Thermodynamics via Truncated Cluster Expansions. https://doi.org/10.1103/physrevlett.92.255702

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