First principles calculations and experiment predictions for iodine vacancy centers in SrI2

Abstract

AbstractWe present the electronic structure, lattice relaxation, and formation energies of iodine vacancy defects in SrI2 for the one‐electron, two‐electron, and ionized charge states. We use a local generalized gradient approximation as well as non‐local hybrid functionals within the framework of density functional theory, as it is commonly accepted that the latter can improve accuracy of the band gap and hence relevant energy levels. Comparison is made to published results on chlorine vacancy defects in NaCl calculated with similar methods and functionals, and also to a recent first‐principles study of one‐ and two‐electron occupancy in MgO vacancy centers. Using the parameters that are calculable from first principles in SrI2 as a starting point, we incorporate available experimental data and adaptations of simple models to predict a range of results that can help guide or interpret future experiments such as absorption energy, configuration coordinate curves, vibrational lineshape, thermal trap depth, and Mollwo–Ivey comparison to alkaline‐earth fluorides. magnified imageCharge density contour in the F center in SrI2.