TITLE:
Electronic Structure of Sodium Thiogermanate
AUTHORS:
Dmytro Ivanovych Bletskan, Vasyl Vasyliovych Vakulchak, Vasyl Mykolaiovych Kabatsii
KEYWORDS:
Sodium Thiogermanate, Electronic Structure, Density of States, Electron Charge Density
JOURNAL NAME:
Open Journal of Inorganic Non-metallic Materials,
Vol.5 No.2,
March
11,
2015
ABSTRACT: Ab initio calculations of the band structure, total and partial densities of states and the spatial distribution of the electron charge density of crystalline Na2GeS3 are performed in the framework of density functional theory in the local density approximation for an exchange-correlation potential. According to the calculation results, sodium thiogermanate is a direct-gap crystal with the top of the valence band and the bottom of the conduction band at the point of the Brillouin zone. The calculated band gap is Eg= 2.51 eV. The nature of the components of the electronic states in different subbands of the valence band is determined. The calculated total density of states in the valence band of the crystal is compared with the known experimental X-ray photoelectron spectrum of Na2GeS3 glass. Based on the maps of the electron density distribution, the nature of the chemical bonds and high mobility of Na+ ions in Na2GeS3 crystal is analyzed.