Electrostatic potential above the (100) surface plane of a face-centred cubic ionic crystal with a continuous three-dimensional electron charge density distribution

Abstract

The electrostatic potential above the (100) surface plane of a face-centred cubic ionic crystal has been calculated using a point-charge distribution for the positive nuclei and a continuous three-dimensional charge-density distribution for electrons. The continuous electron charge distribution has been obtained from the known results of a Fourier crystal-structure analysis. The results for the electric field and its different gradients are compared with those obtained from the previously calculated two-dimensional projected density function and from the Lennard-Jones and Dent model (point-charge distributions for both the positive and negative ions). It is found that the three models differ significantly in their predictions of the electrostatic potential and its derivatives.