The relaxation of atoms around a vacancy in the cubic carbide was determined by using the Tersoff empirical potential. The Haydock-Nex recursion method was used to calculate the density of states arising from atoms around the defect. The outward relaxation of the lattice surrounding an empty site was established. The lattice relaxation resulted in a shift of gap-states towards the conduction band. Vacancy levels of C, at 0.5eV, and of Si at 0.45 and 1.98eV, were revealed in the band-gap. The results were compared with experimental data and with published calculations. It was concluded that it was important to take account of lattice relaxation when analyzing vacancy states in semiconducting compounds.

Deep Gap States of a Single Vacancy in Cubic SiC. V.I.Ivashchenko, V.I.Shevehenko, L.A.Ivashchenko, G.V.Rusakov: Journal of Physics - Condensed Matter, 1999, 11[16], 3265-72