Nonlocal Corrections In Density Functional Theory

We have studied the non-local corrections to the local density approximation (LDA) using a many-body perturbative method. By splitting the total energies into terms corresponding to different orders of self-energy perturbation, we obtain a clear picture of how inclusion of non-local interactions improve LDA total energy. Up to second order (which is equivalent to the same order of the configuration interaction expansion), this formulation gives the correct asymptotic behaviour of the exchange-correlation potential. Numerical calculations for the first two rows atoms give very good ground state energies.