Exchange–correlation errors at harmonic and anharmonic orders: the case of bulk Cu

Bulletin of Materials Science

关键词: Anharmonicity;    density functional theory;    exchange;    correlation;    copper.;   

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

As an aid towards improving the treatment of exchange and correlation effects in electronic structure calculations, it is desirable to have a clear picture of the errors introduced by currently popular approximate exchange–correlation functionals. We have performed ab initio density functional theory and density functional perturbation theory calculations to investigate the thermal properties of bulk Cu, using both the local density approximation (LDA) and the generalized gradient approximation (GGA). Thermal effects are treated within the quasiharmonic approximation. We find that the LDA and GGA errors for anharmonic quantities are an order of magnitude smaller than for harmonic quantities; we argue that this might be a general feature. We also obtain much closer agreement with experiment than earlier, more approximate calculations.

【 授权许可】

CC BY