THE ELECTRON DENSITY DISTRIBUTIONS IN HYDRIDE MOLECULES: I. THE WATER MOLECULE

Abstract

The electron density distribution for the water molecule in its equilibrium configuration is determined by requiring that the forces exerted on the nuclei by this distribution (as calculated by the Hellmann–Feynman theorem) balance the nuclear forces of repulsion. The density distribution is expressed in terms of equivalent orbitals, and to achieve electrostatic equilibrium it is found necessary to have an angle between the bonding orbitals which is less than the structural bond angle (bent bonds), to delocalize the equivalent orbitals and to place the lone pair electrons in sp hybrid orbitals. Further, a discussion of the forces operative in XH2 and XH3 molecules (X = C, N, O) leads to an explanation of the observed bond angles and to general conclusions regarding the hybridization to be expected in such molecules.