A perturbation approach to chemical bonding. Part III. f-Orbital interactions
Abstract
Second-order perturbation theory is used to show that weak interactions between the f orbitals of a central atom and the orbitals of n(n= 2, 3, or 4) symmetry related surrounding atoms are non-directional, provided that the f orbitals are either empty or symmetrically occupied. There is reason to believe that this non-directional character persists for unsymmetrical f- orbital occupation.