Method of Functional Derivatives in the Theory of Point Defects in Crystals: II. General Theory. Total Energy, Electronic Density, and Density of States

A novel method for the calculation of point defect electronic structure in arbitrary crystals in a non‐orthogonal localized atomic orbital basis set, based on the concept of a cluster Green's function and a cluster self‐energy matrix, has been suggested in the preceding paper. In the present paper the general formulas for the total electronic energy, density of states, and electronic density matrix for a defect‐containing crystal are obtained within an approximation analogous to the famous Hedin's GW‐approximation. Besides relevant properties of the cluster Green's function are carefully derived and discussed.