Diamagnetism as a Test of Wave Functions for Some Simple Molecules

A theoretical study is made of the diamagnetism of some simple molecules in a gaseous form, attention being mainly devoted to the ``neon-like'' series Ne, H2O, NH3, and CH4. In this way an attempt is made to gain insight into the way in which the radial electron density distribution within the molecules is influenced, firstly, by the allowance of exchange effects and secondly, by the inclusion of angular terms which must be accounted for in any ``physically real'' description of the electron density. In general, it is found that exchange effects cause the radial density distribution to contract, while the inclusion of angular terms results in the subsequent radial electron density becoming more diffuse.