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Comparison of various exchange potentials in self‐consistent OPW energy band calculations for cubic ZnS and ZnSe
Author(s) -
Stukel D. J.,
Euwema R. N.,
Collins T. C.
Publication year - 2009
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560040741
Subject(s) - pseudopotential , symmetry (geometry) , chemistry , condensed matter physics , dielectric , energy (signal processing) , band gap , exchange interaction , molecular physics , physics , quantum mechanics , mathematics , geometry , ferromagnetism
Self‐consistent energy band calculations using the OPW method have been performed on cubic ZnS and ZnSe using Slater's, Kohn‐Sham's and Liberman's exchange potentials. Term values are given for the four symmetry points T, ≥ X, L , and W. The variation of the energy bands with the exchange coefficient is shown to be linear. The imaginary part of the dielectric constant (ϵE 2 ) is calculated by means of a pseudopotential interpolation technique for the three exchange potentials. It is found that both the band gap and the position of the peaks of the ϵE 2 curves agree very closely with experiment for the self‐consistent results derived from Slater's exchange, while the disagreement is substantial for the self‐consistent results derived from Kohn‐Sham's and Liberman's exchange potential.