Comparison of quantum, classical, and ring-polymer molecular dynamics infra-red spectra of Cl−(H2O) and H+(H2O)2

We present a comparison of the infra-red spectra of Cl−(H2O) and H+(H2O)2 obtained with classical and ring-polymer molecular dynamics with previous quantum calculations. Full-dimensional ab initio-based potential and dipole-moment surfaces are used in these calculations.