All 3d impurities observed to date in tetrahedral semiconductors have a high-spin ground state, in agreement with Hund’s rule. Using first-principles self-consistent Green’s-function calculations for substitutional GaAs:V within the local-spin-density formalism, we predict that the as yet unobserved ground state of GaAs:${\mathrm{V}}^{2+}$ is of the low-spin type. The origin of this unusual ground state is explained.

• Received 11 October 1985

DOI:https://doi.org/10.1103/PhysRevB.33.2961