Ab initio calculations of the F centers in MgF2 bulk and on the (001) surface

We present and discuss the results of atomic and electronic structure calculations of the F centers in MgF ₂ bulk and on the (001) surface. The calculations are based on the B3PW Hartree-Fock and density functional theory hybrid exchange-correlation functional. Most of the electronic density of a missing fluorine ion is localized in the bulk vacancy and a little bit less - in a surface vacancy. It is shown that the electronic F center is a deep donor. The lattice distortion and defect formation energy on the neutral (001) surface and in the bulk are also compared.