G-tensor and hyperfine splitting of , , defect centers in KCl from DFT calculations

Abstract

We have studied the electron paramagnetic resonance (EPR) properties of a classical group of paramagnetic centers in solid KCl, the H center (a trapped species) and the analogous and centers. The calculations have been performed at the density functional theory level using pure and hybrid exchange-correlation functionals in combination with cluster models embedded in point charges. The attention has been focused on the reproduction of key EPR parameters such as the g- and the A-tensors. The A-tensor is satisfactorily reproduced for all three species. The g-tensor is well described in the case of the H center, while large deviations are found for the and trapped radicals. The different behavior is rationalized in terms of different symmetries of the singly occupied molecular orbitals, σ in and π in and .