Hexamer Clusters in MeF2:Yb3+ (MeCa,Sr,Ba)

The electronic structure and g factors of simple impurity centers and hexamer ytterbium clusters in fluorites have been calculated in terms of the exchange charge model. Preliminarily, their local crystal structures have been calculated in the framework of the shell model with the inclusion of lattice distortions near the impurity. Crystal structure and g factors have been calculated of linear cluster Yb-F-Yb-F oriented along a trigonal axis in BaF2.This study was supported by the Federal Agency for Education of the Russian Federation (state contract no. P1462 from 04.09.09)