An Electrostatic Model for Prediction of Shapes of Covalent Molecules and Ions

For covalently bonded molecules and ions containing a central atom and one or more lone electron pairs, oxygen atoms, or sulfur atoms, bond angles can be predicted to within a few degrees by means of an electrostatic model. The parameters required are an electrostatic repulsion number (ERN) for each substituent atom. These ERN's (except for that of fluorine) depend only on the chemical family of the substituent atom and on the period of the central atom. The model emphasizes the strong influence of lone pair electrons on molecular shapes, dipole moments, and other chemical and physical properties.