Computational Toolkit for First-Principles Multicomponent Alloy Thermodynamics

A ``toolkit'' for the simulation of alloy thermodynamics has been developed by integrating first-principles, electronic-structure calculations and the cluster expansion (CE) with Monte Carlo (MC) methods. This Thermal Toolkit (TTK) is aimed at producing reliable thermodynamics of alloys with limited input from the user. Given an alloy, TTK first generates a comprehensive set of structures, automatically submits an electronic-structure calculation to determine the structural energies, stores the structure and its energy in a database,{\footnote {The ``Structural Database'' http://data.mse.uiuc.edu}} then constructs the CE via the structural inversion method that conforms to a set of mathematical conditions to produce an optimal truncated cluster expansion.{\footnote {Nikolai Zarkevich and D.D. Johnson, Phys. Rev. Letts 92, 255702 (2004)}} Using this optimal CE, a MC code (included in TTK) can be used to calculate thermodynamic properties, such as structural phase diagram (T vs c). We present here example application and functionality of TTK on binary and ternary alloy.