Geometries and energy separations of the electronic states of Ge+5 and Sn+5

Abstract

We compute the geometries and energy separations of 13 low-lying electronic states of Ge+5 and Sn+5 with five different structures (edge-capped tetrahedron, C2v; trigonal bipyramid, D3h; tetragonal pyramid, C4v; planar square, D4h; and planar pentagon, D5h). 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 3.77 million configurations are employed. It was found that upon ionization the symmetrical D3h trigonal bipyramidal structures of Ge5 and Sn5 Jahn-Teller distort into nearly degenerate 2B2 and 2A1 electronic states with edge-capped tetrahedral (C2v) geometry. Atomization and dissociation energies of Ge+5 and Sn+5 as well as adiabatic ionization energies of Ge5 and Sn5 are computed. © 1998 American Institute of Physics.