Geometries and energy separations of 28 electronic states of Ge-5

Geometries and energy separations of 28 low-lying electronic states of Ge-5 with different structures (trigonal bipyramid, D-3h; edge-capped tetrahedron, C-2v; tetragonal pyramid, C-4v; planar square, D-4h; planar pentagon, D-5h; linear, D-infinity h; and tetrahedron, T-d) are investigated in this study. We employ the complete active space multiconfiguration self-consistent-field method (CASSCF) followed by large scale multireference singles+doubles configuration interaction (MRSDCI) computations that included up to 3.86 million configurations. Atomization and dissociation energies of Ge-5 are computed and compared with smaller clusters. (C) 1996 American Institute of Physics.