First-Principles Calculations and Thermodynamic Assessment of the Li-Rh and Tl-Tm Systems

Abstract

Abstract-Thermodynamic modeling of the Li-Rh and Tl-Tm systems was carried out via a hybrid approach of CALPHAD (CALculation of PHAse Diagrams) and first-principles calculations. The enthalpies of formation of LiRh, LiRh 3 , Tl 3 Tm, TlTm and Tl 3 Tm 5 are computed via first-principles calculations by using the VASP code. The CALPHAD assessment of Li-Rh and Tl-Tm systems was then performed by considering both the first-principles computed enthalpies of formation and the experimental phase equilibrium data. The liquid phase was modeled with Redlich-Kister polynomial and the five intermetallics compounds were described as stoichiometric compounds. A consistent thermodynamic data set and phase diagrams for the Li-Rh and Tl-Tm systems are obtained.