X-ray Photoelectron Spectrum and Electronic Properties of a Noncentrosymmetric Chalcopyrite Compound HgGa2S4: LDA, GGA, and EV-GGA

0342936 - ÚVGZ 2011 RIV US eng J - Journal Article
Reshak, Ali H - Khenata, R. - Kityk, I. V. - Plucinski, K.J. - Auluck, S.
X-ray Photoelectron Spectrum and Electronic Properties of a Noncentrosymmetric Chalcopyrite Compound HgGa2S4: LDA, GGA, and EV-GGA.
Journal of Physical Chemistry B. Roč. 113, č. 17 (2009), s. 5803-5808. ISSN 1520-6106. E-ISSN 1520-5207
Institutional research plan: CEZ:AV0Z60870520
Keywords : generalized gradient approximation * nonlinear-optical * properties * crystals
Subject RIV: BO - Biophysics
Impact factor: 3.471, year: 2009

An all electron full potential linearized augmented plane wave method has been applied for a theoretical study of the band structure, density of states, and electron charge density of a noncentrosymmetric chalcopyrite compound HgGa2S4 using three different approximations for the exchange cot-relation potential. Our calculations show that the valence band maximum (VBM) and conduction band minimum (CBM) are located at F resulting, in a direct energy gap of about 2.0, 2.2, and 2.8 eV for local density approximation (LDA), generalized gradient approximation (GGA), and Engel-Vosko (EVGGA) compared to the experimental value of 2.84 eV. We notice that EVGGA shows excellent agreement with the experimental data. This agreement is attributed to the fact that the Engel-Vosko GGA formalism optimizes the corresponding potential for band structure calculations. We make a detailed comparison of the density of states deduced from the X-ray photoelectron spectra with our calculations.
Permanent Link: http://hdl.handle.net/11104/0005893