Calculation of hyperfine parameters of positively charged carbon vacancy in SiC

Theoretical simulation of hyperfine parameters for the nearest and next-nearest neighbor atoms of V C + in SiC has been performed for the cubic and hexagonal clusters. The gradient-corrected all-electron DFT calculations with Becke's three-parameter functional have been performed by the use of split valence basis of Gaussian functions with d-functions. High performance of such approximations for the calculation of the hyperfine parameters of the well-known vacancy-related centers in SiC and Si has been demonstrated. We have found the D 2d local symmetry for the V C + in the SiC cubic cluster. In hexagonal-like cluster, the D 2d symmetry is lowered to the C S one. The symmetry plane contains the c -axis and one of the transverse bonds. Four Si atoms of the first shell become essentially inequivalent and have different hyperfine parameters. Two in-plane Si atoms concentrate the major part of the spin density and out-of-plane Si atoms exhibit relatively small hyperfine parameters.