ELECTRONIC-STRUCTURE OF ACTINOCENES AND ACTINOFULLERENES

Spin-orbit configuration-interaction calculations have been carried ou t on actinide complexes using relativistic core potentials and contrac ted Gaussian atomic orbitals. At present, this type of calculation giv es moderate-accuracy results on ground states and excited states and o n a number of molecular properties. Our previous work on uranocene has been continued with protactinocene, neptunocene, and plutonocene, giv ing 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 m ixing of pi orbitals with both 6d and 5f orbitals. The lower states of U@C-28 are of pif and f(2) character with the ground state appearing to be a pif state with mainly singlet character.