| الوصف: |
An approach to nonlinear magnetic properties of a diamagnetic molecule in the presence of a strong homogeneous magnetic field B is proposed, introducing the notion of third-order electronic current density and associated fourth-rank current density tensors via a perturbation expansion. It is shown that cubic magnetic response properties, e.g., fourth-rank magnetizability and fourth-rank nuclear magnetic shielding, can be expressed by relationships alternative to those arrived through perturbation theory by means of third-order current density. A sum rule, providing a condition in integral form for electron charge conservation to the third order in B, has been obtained. |