价键理论新进展

Abstract

概要介绍了现代价键理论的几个主要方法，并讨论了它们各自的特点及其发展现状，并重点介绍了键表方法的基本理论、计算程序及一些应用。

In the present paper a brieF review is given of the historical development in valence bond (VB) theory,The mathematical Formulation of the symmetric group approach For VB theory is summarized,and some important approaches to modern valence bond theory,such as the spin-coupled VB (SCVB),generalized VB(GVB),and VB selF-consistent-Field(VBSCF)approaches are brieFly reviewed.Optimization methods For one electron orbitals are discussed:Fully optimized overlap-enhanced orbitals (OEOs)would probably yield an excellent VB wave Function, even with only a single covalent structure, but would obscure theclassical interpretation,On the other hand,the use of bonded-distorted orbitals (BDOs)provides a clear classical description in terms of an interplay between covalent and ionic structures,Special attention is given to the bonded tableau unitary group approach (BTUGA),a spin-Free VB method:an eFFective algorithm For evaluating Hamiltonian andoverlap matrices is presented,and an ab initio nonorthogonal VB calculation programme is introduced;Furthermore,the BTUGA applications are extensivelv reviewed,which include resonance energy calculations,discussions of molecular structures, potentical energy surFace calculations, discussion of electron transFer in molecules,studies on the excited states,and the inFluence of orbital hybridization on single bond lengths.