Electron structure and density of states’ calculations of Ag 2 S and Ag 2 Se crystals from first-principle

The results of calculations of the electron structure for Ag 2 S and Ag 2 Se crystals from first-principle in the framework of density functional theory (DFT) are presented in this work. The origin of the bands from [Formula: see text] and [Formula: see text] electron states of Ag, S and Se atoms are investigated. It was established that the orthorhombic Ag 2 Se crystal shows semiconductor properties in P222 1 and P2 1 2 1 2 1 space groups and semimetallic properties in Im-3m space groups with cubic crystal system. Monoclinic crystal type of Ag 2 S shows semiconductor properties in P2 1 /c space group. However, semimetallic properties manifested itself in monoclinic Ag 2 S in P2 1 and cubic Ag 2 S structure in Im-3m phases.