Probing the LDA-1/2 method as a starting point for G(0)W(0) calculations

Article

关键词: BAND PARAMETERS;    GREENS-FUNCTION;    III-V;    PHOTOEMISSION;    SEMICONDUCTORS;    MOLECULES;   

DOI  :  10.1103/PhysRevB.94.235141

来源: SCIE

【 摘 要 】

By employing the G(0)W(0) approximation of Hedin's GW approach one can obtain quasiparticle energies of extended systems and molecules with good accuracy. However, for many materials, semilocal exchange-correlation functionals are unsatisfactory starting points for G(0)W(0) calculations. Hybrid functionals often improve upon them, but at a substantially higher computational cost. As an alternative, we suggest the LDA-1/2 method, which provides reasonable band gaps without being computationally involved. In this work, we systematically compare three starting points for G(0)W(0): LDA, PBE0, and LDA-1/2. A selection of solids is chosen for this benchmark: C, Si, SiC, AlP, LiF, MgO, Ne, Ar, GaN, GaAs, CdS, ZnS, and ZnO. We demonstrate that LDA-1/2 is a good starting point in most cases, reducing the mean absolute error of band gaps by 50% when compared with the other two functionals.

【 授权许可】

Free