Electronic structure and electron charge density in the interatomic bonds of bisbr and bisebr crystals

摘要

Electronic structure and electronic charge density in the interatomic bonds are investigated with ab initio calculations based on the density-functional theory. The full potential linearized augmented plane-wave method was used with the generalized gradient approximation. Considering the partial density of states the electron charge density distribution in the Bi, S, Se and Br atomic bonds is caused by Bi-6p, S-3p, Se-4p, Br-4p orbital hybridization. Electronic charge distribution of one BiSBr and BiSeBr molecule range suggest that the Bi-S, Bi-Se and Bi-Br bonds are covalent-ionic type. Bi-S and Bi-Se bonds are strong covalent with a not great ionicity factor ($fi^P = 0.060$, Bi-S; $fi^P = 0.039$, Bi-Se). Bi-Br bonds are covalent type with a larger ionicity factor ($fi^P = 0.147$, Bi-Br).