FRAGMENT CALCULATION OF ELECTRONIC-STRUCTURES OF POLYATOMIC-MOLECULESIN THE GROUND-STATE .2. A METHOD OF DELOCALIZED STATES OF FRAGMENTS

A fragment method is proposed to calculate the electronic structures o f polyatomic molecules in the ground state. Localization and delocaliz ation of the electronic states of molecular fragments are calculated s imultaneously. The compact formulation of the method allows algorithmi cally efficient calculations of the electronic structures of interacti ng molecular fragments as well as of the whole molecules.