The equilibrium structure and relative energy of cis- and trans-hydroxysilylene, HSiOH

The equilibrium structure of the cis and trans isomers of hydroxysilylene, HSiOH, has been determined from large-scale ab initio calculations using the coupled-cluster method, CCSD(T), with basis sets of double- through quintuple-zeta quality. The effects of core-electron correlation on the calculated molecular parameters were investigated. The complete-basis-set limits of the molecular parameters were estimated using various extrapolation techniques. At 0 K, the cis isomer is predicted to be more stable than the trans isomer by merely 0.04±0.03 kcal/mol.