Gradient-level and nonlocal density functional descriptions of Cu-Au intermetallic compounds



: Henrik Levämäki, Liyun Tian, Kalevi Kokko, Levente Vitos

Publisher: SPRINGER

: 2018

: European Physical Journal B: Condensed Matter and Complex Systems

: EUROPEAN PHYSICAL JOURNAL B

: EUR PHYS J B

: ARTN 128

: 91

: 6

: 7

: 1434-6028

DOI: https://doi.org/10.1140/epjb/o2018-90166-9

: https://link.springer.com/article/10.1140/epjb/e2018-90166-9

: https://research.utu.fi/converis/portal/detail/Publication/32192792


We use three gradient level and two nonlocal density functional approximations to study the thermodynamic properties of Cu-Au compounds. It is found that a well-designed gradient level approximation (quasi non-uniform approximation, QNA) reproduces the experimental equilibrium volumes and the formation energies of L12 and L10 phases. On the other hand, QNA predicts a non-existent beta(2) phase, which can be remedied only when employing the nonlocal hybrid-level Heyd-Scuseria-Ernzerhof (HSE06) or Perdew-Burke-Ernzerhof (PBE0) approximations. Gradient-level approximations lead to similar electronic structures for the Cu-Au compounds whereas hybrids shift the d-band towards negative energies and account for the complex d-d hybridization more accurately.

Last updated on 2024-26-11 at 13:13