Theoretical Study of the Effect of Pressure on the Electronic Structure of Grey Tin

Abstract

A large unit cell (LUC) within intermediate neglect of differential overlap (INDO) formalism has been used to estimate the electronic properties of Sn and their pressure dependence. The calculated properties are, in general, in acceptable agreement with the available experimental values except the direct band gap. The calculated properties follow the usual qualitative trends that can be obtained from Hartree-Fock analysis. The increase of pressure is predicted to cause: a linear increase of the direct band gap with a pressure coefficient of 0.06 eV/GPa, a linear increase of the valence band width, a decrease of the conduction band width, a slight decrease of the electronic occupation probability for the s orbital with a slight increase of this probability for the p orbital, and a decrease of the X-ray scattering factors.