Finite-temperature effects on the stability and infrared spectra of HCl(H2O)6 clusters.

Theoretical studies of the interaction of HCl with small water clusters have so far neglected the effect of temperature, which ranges from a few tens of kelvin in cluster experiments, up to about 250 K in typical atmospheric conditions. We study the dynamical behavior of a selected set of HCl(H2O)6 clusters, representative of undissociated and dissociated configurations, by means of DFT-based first principles molecular dynamics. We find that the thermodynamcal stability of different configurations can be affected by temperature. We also present the infrared spectra of dissociated and undissociated configurations at 200 K and discuss the origin of the spectral features.