Testing and Extending VSEPR with WebMO and MOPAC or GAMESS

VSEPR is a topic that is commonly taught in undergraduate chemistry courses. The readily available Web-based program WebMO, in conjunction with the computational chemistry programs MOPAC and GAMESS, is used to quantitatively test a wide range of predictions of VSEPR. These predictions refer to the point group of the molecule, including the influence of lone pairs on bond angles (introductory course) as well as the effect of lone pairs and other bonds on bond lengths, the influence of multiple bonds and electronegativity, and preferred location of ligands in heteroleptic compounds (topics covered in courses beyond the introductory level). The qualitative predictions of VSEPR are augmented with quantitative results.