On the solvation model and infrared spectroscopy of liquid water

Abstract

The IR spectra of liquid water (in both protonated and deuterated variants) are simulated with DFT calculations including the dispersion correction. Using a cluster model with up to 15 water molecules, the continuum solvation approach, and a common Lorentzian dressing of the calculated frequencies, the resulting IR curves are found to mimic well the observed counterparts. Contrasting with existing molecular dynamics simulations, the present a priori approach is further shown to accelerate convergence, with 15 molecules being enough for the endeavor. The proposed scheme is then expected to eliminate any peaks and shoulders that tend to arise in gas-phase calculations.