Self-consistent molecular-cluster calculations of the electric field gradient of 5spimpurities(47Ag–54Xe) in cadmium

The electric field gradients (EFG’s) of 5sp impurities ${(}_{47}$Ag${–}_{54}$Xe) are calculated within the self-consistent local-density molecular-cluster approach using 27 atoms. The experimentally observed oscillation of the EFG, from ${}_{47}{}^{}{}_{}{}^{}\mathrm{Ag}$ to ${}_{54}{}^{}{}_{}{}^{}\mathrm{Xe}$, originates from the conduction-electron contribution. The 5p impurity electrons hybridize with the conduction band into bonding and antibonding states, the $p_x$,$p_y$ bonding states having the lowest energy. A successive population of these states, with increasing impurity charge, explains the change in sign that occurs close to ${}_{51}{}^{}{}_{}{}^{}\mathrm{Sb}$.