ELECTRONIC-STRUCTURE OF ACTINOCENES AND ACTINOFULLERENES

Spin-orbit configuration-interaction calculations have been carried out on actinide complexes using relativistic core potentials and contracted Gaussian atomic orbitals. At present, this type of calculation gives moderate-accuracy results on ground states and excited states and on a number of molecular properties. Our previous work on uranocene has been continued with protactinocene, neptunocene, and plutonocene, giving the patterns of low-lying f --> f states and higher-lying f --> d and pi --> d states. Accurate magnetic moment values are obtained from these wavefunctions. The U@C-60 and U@C-28 complexes show extensive mixing of pi orbitals with both 6d and 5f orbitals. The lower states of U@C-28 are of pi*f and f(2) character with the ground state appearing to be a pi*f state with mainly singlet character.