Study of hole and exciton autolocalization in a calcium fluoride crystal by means of molecular dynamics from first principles

Abstract

Results from theoretical simulations of an autolocalized hole (V_k center) and an autolocalized exciton in CaF₂ crystal by meand of ab initio molecular dynamics are presented. All calculations are performed using the density functional theory in the DFT + U approximation. Mechanisms of the diffusion of the V_k center and restructuring between different configurations of an autolocalized exciton in the free crystal and in the presence of the axial stress are identified by simulating the molecular dynamics in the 50 to 450 K range of temperatures.