Striking similarities between elementary silicon and aluminum compounds: monobridged, dibridged, trans-bent, and vinylidene isomers of aluminum hydride (Al2H2)

Abstract

Ab initio quantum mechanical methods five been used to study the singlet potential energy surface of Al 2 H 2 . Optimum geometries and harmonic vibrational frequencies were obtained for four geometrical isomers using the self-consistent-field (SCF), configuration interaction (CI), and coupled cluster (CC) methods. Both correlation methods including single and double excitations (CISD, CCSD) were employed, and all wave functions were determined with both DZP and TZ2P basis sets. Final energy predictions are obtained using large atomic natural orbital basis sets, and including the effects of triple excitations perturbatively using CCSD(T) methods. We found the planar dibridged structure to be the global minimum, as predicted earlier by Baird