Note on Diamagnetic Anisotropy and the Method of Molecular Orbitals

The simple London theory of the diamagnetic anisotropy of organic molecules containing benzene rings is modified to include the effect of a non-orthogonality of 25 percent between atomic wave functions on adjacent atoms. Except in the case of diphenyl the effect of such a modification is surprisingly small; that is, although the contributions to the anisotropy from individual electronic orbits is materially changed the resultant contribution of all the electrons is hardly altered. The significance of this result is discussed.