Ab initio prediction of the structure, harmonic vibrational frequencies, and dissociation energy of the H2–GeH+3–H2 cluster ion

Abstract

Ab initio predictions of the molecular geometry, harmonic vibrational frequencies, and dissociation energies are reported for the germanium hydride cluster ion GeH+7. Seven stationary points were located on the potential energy surface (PES) of GeH+7 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(3d1f,1p) quality basis set. The most stable structure has a C2 symmetry with the two H2 subunits rotating freely about the symmetry axis of the GeH+3 fragment. Our best estimate of the dissociation energy for GeH+7, 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 SiH+7 and CH+7 cluster ions.