Calculation of electric field gradients in metals

Abstract
The electric field gradient (EFG) at a nucleus in the metals Be, Mg, Zn, Cd and In has been calculated. Pseudopotential theory is used and only conduction electrons external to the ion core at the origin are considered. The conduction electrons are found to produce an EFG which partly screens the ionic contribution. Good agreement with experiment is found for Be but the calculated values in Mg, Cd and In are smaller than the experimental values and it is concluded that the conduction electrons within the ion core at the origin make a large contribution to the EFG at the nucleus in these cases.