A SIMPLIFIED CHARGE-TRANSFER MODEL - CALCULATIONS USING AN EXPLICIT KINETIC-ENERGY FUNCTIONAL

A charge transfer calculation which uses an explicit kinetic energy fu nctional is reported. By combining the implicit Poisson equation (Andr ew E. DePristo, Phy. Rev. A, 54, 3863 (1996)) with the Thomas-Fermi ki netic energy functional, we developed a new scheme to calculate charge transfer in a crystal system. The applicability of this scheme is inv estigated for SnO2 crystals, where the variation of total charge in a muffin-tin sphere is analyzed as a function of lattice constant and th e results of these analyses are compared with the exact result calcula ted by using the full potential augmented wave method. Our new scheme is found to predict correct direction of charge transfer. (C) 1998 Els evier Science S.A. All rights reserved.