Predicting the accurate structural and energetic properties of copper-gold alloys using random phase approximation

The ground-state equilibrium properties of copper-gold alloys have been explored with the state-of-the-art random phase approximation (RPA) [1]. The PBE, PBE revised for solids, and revised Tao-Perdew-Staroverov-Scuseria functionals by Perdew et al. predict too-low formation energies, while the SCAN slightly overestimates it. The inclusion of thermal correction or the long-range dispersion provides a negligible contribution to the formation energies estimated with semilocal density functional theory. The spin-orbit coupling improves the formation energies of PBE only by 7-8 meV, while it intensifies the overestimation of SCAN. We found that the nonlocality present in RPA is able to describe the transition between two delocalized electron densities (bulk elemental constituents to crystallized alloys), as required to provide accurate formation energies without any further corrections.


[1] N. K. Nepal, et al., Phys. Rev. B 100 (04), 045135 (2019)