Theoretical Study on the Hydrogen-Bonding Effect of H2On-H2Om (n=1-4, m=1-4) Dimers

The DFT and ab initio calculations have been performed to elucidate hydrogen interaction of hydrogen polyox- ide dimers, H2On-H2Om (n=1-4, m=1-4). The optimized geometries, harmonic vibrational frequencies, and binding energies are predicted at various levels of theory. The harmonic vibrational frequencies of the molecules considered in this study show all real numbers implying true minima. The higher-order correlation effect were discussed to compare MP2 result with CCSD(T) single point energy. The binding energies were corrected for the zero-point vibrational energy (ZPVE) and basis set superposition errors (BSSE). The largest binding energy predicted at the CCSD(T)/cc-pVTZ level of theory is 8.18 kcal/mol for H2O4-H2O3 and the binding energy of water dimer is predicted to be 3.00 kcal/mol.