Some investigations in the theory of open-shell ions

Abstract

The use of V, W and X coefficients in calculations of matrix elements is shown. General formulae for all two-electron spin-orbit coupling matrices in an octahedral strong-field coupling scheme are deduced. The parametrization of the electrostatic energy in ligand field theory is discussed and the number of parameters required is given in various cases. The configuration f ² in an octahedral strong-field scheme is treated in some detail and reasons for the anomalously low paramagnetism of PuF₆ are exposed, largely in contradiction to earlier views [13, 14]. Finally it is shown that expressions involving recoupling matrix elements, which occur in a scheme for calculating matrix elements of one-electron operators given by Tanabe and Kamimura [3], are proportional to W and X coefficients, thus considerably extending the scope of the latter work.