BULK PROPERTIES FROM FINITE-CLUSTER CALCULATIONS .5. PSEUDO-WANNIER ORBITALS FROM MOLECULAR-ORBITAL CALCULATIONS ON FINITE CLUSTERS

A unitary transformation of the canonical Hartree-Fock orbitale which yields pseudo-Wannier orbitale in periodic finite systems is introduced. These orbitale are localized within individual unit cells and therefore can serve as a suitable one-electron basis for calculating the electron correlation energy. They also provide a natural partitioning scheme which allows for studying the finite-size effects on the total energy and the first-order electronic properties. The similarity sum which is maximized by the above transformation can serve as a measure of deviation of the electronic distribution in the system under consideration from that of an infinite periodic system. © 1990 American Institute of Physics.