Elementary constituents of microdevices: the Ge2H fragment.

Highly correlated ab initio electronic structure theory has been used to systematically investigate the linear (XΠ2) GeGeH and H-bridged (XB12 and AA12) GeHGe structures and the isomerization transition state (AA′2) connecting XΠ2 with AA12. The equilibrium structures and physical properties have been predicted employing self-consistent field, configuration interaction with single and double excitations, coupled cluster with single and double excitations (CCSD), and CCSD with perturbative triple excitations [CCSD(T)]. Four correlation-consistent polarized valence-[cc-pVXZ and aug-cc-pVXZ (X=T and Q)] type basis sets were used in the study. For the H-bridged GeHGe isomer, the XB12 ground state is predicted to lie only 0.74 [0.95 with zero-point vibrational energy (ZPVE) corrections] kcalmol−1 below the AA12 excited state at the CCSD(T) level of theory with the augmented correlation-consistent polarized valence quadruple zeta (aug-cc-pVQZ) basis set. The XB12 state of the H-bridged GeHGe isomer lie...