An ab initio study on the equilibrium structure and torsional potential energy function of disulfane

The molecular parameters of disulfane, H2S2, have been determined in large-scale ab initio calculations using the coupled-cluster method, CCSD(T), and the basis sets of double- to quadruple-zeta quality. With the largest basis set employed, cc-pVQZ, the equilibrium parameters are determined to be r(SS) = 2.0670 Å, r(SH) = 1.3430 Å, ∠(SSH) = 97.98°, ∠ (HSSH) = 90.66°, Vtrans = 1958 cm−1, and Vcis = 2714 cm−1.