Computer Simulation of the Electronic Structures and Absorption Spectra for a KMgF3 Crystal Containing a Potassium Vacancy

摘要

CASTEP code, based on the density functional theory(DFT) Electronic structures and absorption spectra for a perfect KMgF3 crystal and a KMgF3 crystal containing a potassium vacancy V-K are optimized using the CASTEP density functional theory code. The calculated results indicate that the perfect KMgF3 crystal has no absorption in the visible energy region, however, a KMgF3 crystal containing V-K has an additional absorption band peaking at 565 nm, fitting well with the experimental result that KMgF3 irradiated by an electron has an additional absorption peak at 565 nm. It is reasonably predicted that the 565 nm absorption band is related to the existence of V-K in the KMgF3 crystal created by the electron irradiation.