“…In the previous section, the valence electrons about an atom in a molecule wore pictured in localized orbitals. The advantages of partitioning the electron cloud of a molecule into localized, nonoverlapping parts, called in molecular orbital theory equivalent, orbitals, have been discussed by several authors (48,112,120,161,163,178,247,271). Two types of localized orbitals are frequently encountered: orbitals occupied by unshared, nonbonding electrons, and orbitals occupied by bonding or shared electrons.…”