The application of strictly localized geminals to the description of chemical bonds

✍ Scribed by Raymond A. Poirier; Péter R. Surján

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 457 KB
• Volume: 8
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540080421

✦ Synopsis

A theory is developed in which closed-shell molecules are viewed as systems of weakly interacting chemical bonds. Composite-particle creation operators obtained by an appropriate quasiparticle transformation are used to create the wave function of two-electron bonds. These quasiparticles are bosons, since they are composed of two electrons, but the total many-electron wave function is properly antisymmetric. The inteimal structure of the quasi-Bose-particles is affected by inductive interbond interactions. Delocalization and dispersion interactions between different bonds are neglected, thus the approach corresponds to a first-order many-body PT (Perturbation Theory) with a correlated, but fully localized, reference state. The whole formalism is developed ab initio. The nonorthogonality problem is handled by a biorthogonal formulation. To illustrate the effectiveness of the model, numerical calculations are reported.