# name
First-principles study of the optical transitions of F centers in the bulk and on the (0001) surface of (alpha)-Al2O3

# metadata.dc.description.abstract[].value
The electronic structure and spectroscopic features of the optical spectra of oxygen vacancies in the bulk and
on the  0001 surface of  -Al2O3 have been studied by first-principles methods. The effect of oxygen vacancies
on the crystalline structure has been determined by the appropriate atomic structure optimization carried out
using a periodic model and density functional theory  DFT calculations. Both, neutral  F center and charged
 F+ center oxygen vacancies have been considered. Optical transitions arising from the excitations of the
electron s trapped in the F+ and F centers, both on the surface and in the bulk of the material, have been
studied using a suitable embedded cluster model approach. The cluster geometry, including the relaxation
around the vacancy, has been taken from the periodic calculations. The transition energies and intensities have
been obtained by applying the explicitly correlated multiconfigurational second-order perturbation theory
method and also time-dependent DFT approaches. The present results are in good agreement with available
experimental data for the bulk and provide a guide to interpret forthcoming experiments involving the spectroscopy
of oxygen vacancies present in irradiated or defective  -Al2O3 0001 surfaces.

# metadata.dc.relation.isformatof[].value
Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevB.72.054109

# metadata.dc.source[].value
Articles publicats en revistes (Ciència dels Materials i Química Física)

# metadata.dc.title[].value
First-principles study of the optical transitions of F centers in the bulk and on the (0001) surface of (alpha)-Al2O3