THEORETICAL-STUDY OF THE MAGNETIC-PROPERTIES OF WATER-MOLECULES IN NONUNIFORM MAGNETIC-FIELDS

The interaction Hamiltonian within the Bloch gauge for the potentials of the electromagnetic field has been used to define electromagnetic m ultipole moment operators and operators for the magnetic field of elec trons acting on the nuclei of a molecule. Perturbation theory has been applied to evaluate the induced electronic moments and magnetic field at the nuclei. Multipole magnetic susceptibility and nuclear magnetic shielding tensors have been defined to describe the contributions ari sing in non-uniform magnetic fields, and their origin dependence has b een analyzed. Extended numerical tests on the water molecule in a stat ic, non-uniform magnetic field have been carried out, using the random -phase approximation within the framework of accurate Hartree-Fock zer o-order wavefunctions.