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 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. (C) 2001 Elsevier Science B.V. All rights reserved.