ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 53, Number 1
JKCSEZ 53(1)
February 20, 2009 

The global minimum structures of the benzene-water, Bz-H₂O and benzene-water cation complex, [Bz-H₂O]⁺ have been investigated using ab initio and density functional theory(DFT) with very large basis sets. The highest levels of theory employed in this study are B3LYP/cc-pVQZ for geometry optimization and MP2/aug-cc-pVTZ//B3LYP/aug-cc-pVTZ for binding energy. The harmonic vibrational frequencies and IR intensities are also determined at the various levels of theory to confirm whether the structure of water complex is affected by the presence of benzene. The binding energies of Bz-H₂O (N-1) structure are predicted to be 3.92 kcal/mol (D_e) and 3.11 kcal/mol (D₀) after the zero-point vibrational energy correction at the MP2/cc-pVQZ//B3LYP/cc-pVQZ level of theory. The binding energies of [Bz-H₂O]+ (C-1) structure are predicted to be 9.06 kcal/mol for De and 7.82 kcal/mol for D₀ at the same level of theory.