Electronic Structure of Sodium Thiogermanate

Dmytro Ivanovych Bletskan¹, Vasyl Vasyliovych Vakulchak¹, Vasyl Mykolaiovych Kabatsii²

¹Department of Physics, Uzhgorod National University, Uzhgorod, Ukraine.
²Mukachevo State University, Mukachevo, Ukraine.

DOI: 10.4236/ojinm.2015.52004                

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 E_g= 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.

Keywords

Sodium Thiogermanate, Electronic Structure, Density of States, Electron Charge Density

Conflicts of Interest

The authors declare no conflicts of interest.

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