F center in LiF: A quantum mechanical ab initio investigation of the hyperfine interaction between the unpaired electron at the vacancy and its firstseven neighbors - art. no. 235102

The paramagnetic F center in LiF is investigated at a quantum mechanical le vel with the CRYSTAL98 periodic code by using a supercell scheme. The isotr opic and anisotropic components of the hyperfine coupling tensor describing the interaction between the unpaired electron and the nuclear spins up to the seventh nearest neighbors of the defect are computed by using two diffe rent Hamiltonians (Hartree-Fock and local density approximation), and turn out to compare reasonably well with electron paramagnetic resonance and ele ctron-nuclear double resonance data. A term of the hyperfine tensor, not ye t available experimentally, is presented for future comparison. The defect wave function is analyzed in terms of the charge and spin density maps, ban d structure, and Mulliken population.