Dielectric constant of water from free energies of H-bond formation in (H2O)n clusters

Free energies of formation of (H2O)n clusters (n = 2–20), calculated at a number of levels of theory by Mejias and Lago [J.A. Mejias, S. Lago, J. Chem. Phys., 113 (2000) 7306] and by Day and Pachter [P. Day, R. Pachter, J. Chem. Phys., 112 (2000) 2063], have been utilised to calculate the Kirkwood–Frohlich correlation factor and static dielectric constant (ε) of water at a number of temperatures. Results are in fair agreement with experimental values. The calculated ε values follow the same decreasing trend with increase in temperature as the experimental values.