Can the OH stretch vibrational spectra of (H2O)n clusters (n=1–6) be estimated from an empirical many-body model and a polynomial OH stretch potential?

An intramolecular potential term (expressed as a series expansion in terms of internal coordinates) has been introduced in the water many-body model TCPE to estimate the water cluster OH stretch vibrational spectrum. Model parameters are derived from experimental results on (H2O)n clusters (n=1–5). OH stretch vibrational spectra of three water hexamers computed with TCPE are in good agreement with available ab initio computations, and, as compared to experimental data, TCPE results also agree with the assignment of the experimental benzene–(H2O)6 OH spectrum to a structure where water adopts a three-dimensional cage like structure π-hydrogen bonded to benzene.