Nonlocal exchange energy of many-fermion systems of arbitrary dimensionality and interparticle interaction

Abstract

The exchange contributions to the ground-state energy of an inhomogeneous many-fermion system of arbitrary dimensionality are calculated. Explicit results are given for both the local-density approximation and the lowest-order gradient corrections for a class of interparticle interactions, including the Coulomb potential. For wider application, both the local-density approximation and the gradient corrections are decomposed into their wave-vector components. These exchange contributions can then be determined for arbitrary interparticle interaction by a simple quadrature