title: First-principles calculations for the H center in SrF2 crystals.
abstract: The ground state of H-center systems for the SrF(2) crystal is simulated with two different arrangements, which are oriented along either [100] or [111] axes. The calculations are based on hybrid Hartree-Fock and density functional theory exchange functionals by using Becke's three-parameter method combined with the nonlocal correlation functionals of Perdew and Wang. The energy difference between H centers with different orientations shows that the H center oriented in the [111] direction in alkaline earth fluorides is the most stable configuration. The geometric relaxations of the neighboring atoms surrounding the H centers are presented. The combination energy of an H center and the formation energy of the related F-H pair in both alkaline earth fluorides are discussed. We report also the electronic structure of the H center systems. The effective charges and spins of the substitutional and interstitial fluorine atoms show that the hole is located at the interstitial fluorine in the system with the [111] orientation of the H center. The band structures are illustrated. With the help of studying the total and partial density of states, the constituents of the defect bands are clarified.
authors.affiliation: Fachbereich Physik, Universität Osnabrück, D-49069 Osnabrück, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Yue
authors.forename: R
authors.initials: R
authors.lastname: Jia
authors.forename: H
authors.initials: H
authors.lastname: Shi
authors.forename: X
authors.initials: X
authors.lastname: He
authors.forename: R I
authors.initials: RI
authors.lastname: Eglitis