AbstractThe method developed in Parts I, II for calculating the polarization energy of crystals by point defects self‐consistently with their electronic structure is extended. (i) Along with the initial (e.g. ground) state the final (e.g. excited) electronic state of the crystal containing the defect and the corresponding vertical transition energy is considered. (ii) The uncompensated charge density simulating the defect and its neighbourhood is treated now by a set of non‐point charges. (iii) The polarization potential is calculated. This generalized method may be useful for self‐consistent calculations of a wide class of actual point defects in ionic s