Improved electronic structure and optical properties of sp-hybridized semiconductors using LDA+U SIC
AUTOR(ES)
Persson, Clas, Mirbt, Susanne
FONTE
Brazilian Journal of Physics
DATA DE PUBLICAÇÃO
2006-06
RESUMO
We propose the local density approximation (LDA) plus an on-site Coulomb self-interaction-like correction (SIC) potential for describing sp-hybridized bonds in semiconductors and insulators. We motivate the present LDA+U SIC scheme by comparing the exact exchange (EXX) hole with the LDA exchange hole. The LDA+U SIC method yields good band-gap energies Eg and dielectric constants epsilon(omega ~ 0) of Si, Ge, GaAs, and ZnSe. We also show that LDA consistently underestimates the gamma-point effective electron m c and light-hole m lh masses, and the underlying reason for this is a too strong light-hole-electron coupling within LDA. The advantages of the LDA+U SIC approach are a computational time of the same order as the ordinary LDA, the orbital dependent LDA+U SIC exchange-correlation interaction is asymmetric analogously to the EXX potential, and the method can be used for materials and compounds involving localized d- and f-orbitals.
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