Effective interaction energy of water dimer at room temperature: An experimental and theoretical study.

Buffer-gas pressure broadening for the ν1+ν3 band of H2O at 1.34–1.44 μm for a variety of buffer gases was investigated at room temperature using continuous-wave cavity ring-down spectroscopy. The effective interaction energy of water dimer under room temperature conditions was evaluated from the pressure broadening coefficients for rare gases using Permenter-Seaver’s relation. Monte Carlo simulations were performed using ab initio molecular orbital calculations to evaluate the interaction energies for the water dimer at 300 K. In this theoretical calculation, the orientations of the two water molecules were statistically treated. [ABSTRACT FROM AUTHOR]