Distribution of Electrons in the Water Molecule

Abstract

The electron distribution in H₂O is examined using the wave functions of Ellison and Shull (ES) and the density averaged over all orientations about the O nucleus is computed. This is compared with that calculated from the simple central field wave functions used previously by the authors in the interpretation of x‐ray scattering results, and there is good agreement between these densities. In addition to the s term in the expansion of the ES density in spherical harmonics, the p term is also exhibited explicitly; it is this which determines the dipole moment of the molecule. In the second part of the paper a general method is developed for the calculation of the x‐ray scattering by a gas of nonspherical molecules. Using this formulation together with the ES density for H₂O it is shown that the p term has only a very small effect on the scattering factor. The results using the ES density are in good agreement with those obtained previously and with experiment.