Energy property and covalency of H2S···X (X = N2, CO, CS and SiO) hydrogen bond

CCSD(T) calculations on H2S…X (X = N2, CO, CS and SiO) series provide reliable structures, energy properties and covalency of hydrogen bonds (HB). Symmetry adapted perturbation theory analysis demonstrates the dominant role of electrostatic interactions for the relative stronger HBs; and the dispersion demonstrates the attraction of the very weak HB of H2S…N2. Upon formation of HBs, the electrostatic and dispersion energies play important role. The covalent character is analyzed by AIM theory and topological analysis on electron density functions; and it suggests the very weak strength of HBs with non-covalent character.