Using the B3PW method, the ground state of H center systems for CaF2 and BaF2 crystals was simulated. The energy difference between H centers with different orientations showed that the H center oriented in the [111] direction in alkaline earth fluorides was the most stable. The geometric relaxations of the neighbouring atoms surrounding the H center were deduced. The combination energy of a H center and the formation energy of the related F–H pair in both alkaline earth fluorides was considered. Also reported was the electronic structure of the H center systems. The effective charges and spins of the substitutional and interstitial fluorine atoms showed that the hole was located at the interstitial fluorine. By studying the DOS sketches the constituents of the defect bands were clarified.

The Atomic and Electronic Structure of CaF2 and BaF2 Crystals with H Centers: a Hybrid DFT Calculation Study. R.Jia, H.Shi, G.Borstel: Journal of Physics - Condensed Matter, 2010, 22[5], 055501