X-ALPHA VALENCE BOND THEORY OF WEAK ELECTRONIC COUPLING - APPLICATION TO THE LOW-LYING STATES OF MO2CL84-

We show that valence bond (VB) concepts can be introduced into Xα theory. The resulting Xα-VB model yields energy states which either are pure multiplets or can be combined by straightforward projection to give pure multiplets. The new theory should be more computationally efficient than Hartree-Fock-based CI models. A preliminary study of the δ→δ * transition in Mo2Cl84- yields an excitation energy closer to experiment than previous theoretical values, including those obtained to date from GVB-CI calculations. © 1979 American Institute of Physics.