A study of the silagermylyne (SiGeH2) molecule: A new monobridged structure

Ab initio molecular orbital theory has been used to study the various structures of the SiGeH2 system. Utilizing the DZP basis set in conjunction with five correlated methods, the most intricate being coupled-cluster theory including single, double, and perturbative triple excitations [CCSD(T)], a study of the potential energy surface of the SiGeH2 system was conducted. Equilibrium geometries, harmonic vibrational frequencies, dipole moments, and infrared intensities of the nonplanar dibridged structure, asymmetrical monobridged structures, vinylidenelike structures, trans structure, and linear structure are presented. As anticipated, the dibridged structure was the global minimum, with the novel cis monobridges and a vinylidenelike structure being low lying minima as well, lying within 10 kcal mol−1 of the dibridged global minimum. The two monobridged isomers are predicted to be the third and fourth most stable minima. © 1995 John Wiley & Sons, Inc.