The evaluation of the hyperfine interaction tensor components in molecular systems

In this paper a general method is developed to evaluate the nine hyperfine interaction tensor components, Aαβ, arising from the electron orbital angular momentum and the electron spin dipolar-nuclear spin angular momentum interactions of an electron associated dominantly with one nucleus coupling with a nucleus with a non-zero magnetic moment, where the electronic wavefunction is described by a Slater-type orbital. The method handles long range and short range coupling including the free atom case. From the results the degree of non-coincidence of the principal axes of the g and A tensors and the n.m.r. shifts are evaluated. As an illustration the molecular system examined is a molecule containing a d¹ transition metal ion in a strong crystal field.