AB-INITIO PREDICTION OF THE STRUCTURE, HARMONIC VIBRATIONAL FREQUENCIES, AND DISSOCIATION-ENERGY OF THE H-2-GEH3+-H-2 CLUSTER ION

Ab initio predictions of the molecular geometry, harmonic vibrational frequencies, and dissociation energies are reported for the germanium hydride cluster ion GeH7+. Seven stationary points were located on the potential energy surface (PES) of GeH7+ using the self-consistent field (SCF), configuration interaction including single and double excitations (CISD), and coupled cluster including single, double, and perturbatively included triple excitations [CCSD(T)] methods in conjunction with a double-ζ plus polarization (DZP) and a triple-ζ plus polarization TZ(3 d 1 f, 1 p) quality basis set. The most stable structure has a C 2 symmetry with the two H2 subunits rotating freely about the symmetry axis of the GeH3+ fragment. Our best estimate of the dissociation energy for GeH7+, taking into account the zero point vibrational energy (ZPVE) is 3.10 kcal/mol compared to 4.6 and 1.2 kcal/mol obtained, respectively, for the SiH7+ and CH7+ cluster ions. © 1995 American Institute of Physics.