The electron densities obtained from the S.C.F. wave functions determined by Ransil for some first-row homonuclear diatomic molecules are tested through a calculation of the forces acting on the nuclei. None of the density functions (for Li2, Be2, C2, N2, and F2) give the required condition of electrostatic equilibrium, the departure from a nonzero force increasing with increasing nuclear charge. Adverse atomic polarizations are shown to be primarily responsible for these results, and in particular for the surprising result that the density in the 3σg orbital of N2 and F2 actually exerts a force tending to separate the molecule into atoms.
