Sensitivity analysis of a polarizable water model

Recently, we have extended the combined sensitivity analysis/molecular dynamics method1,2 to identify the most important parameters of the flexible SPC and TIP3P water models in determining the thermodynamical and structural properties of liquid water.3,4 Since the SPC and the TIP3P models do not include molecular polarizability explicitly, it is difficult to examine the role of molecular polarizability in determining the properties of liquid water. In this paper, we carry out a sensitivity analysis on a newly developed polarizable water model. We have systematically investigated the possible responses of the structural and thermodynamical properties of this polarizable water model when the potential parameters of the model are perturbed. Discovered is the particularly important role of molecular polarization in describing the properties of liquid water. On the other hand, the use of a point-charge, rather than a dispersed-charge, model appears to be adequate for simulating liquid water. In conjunction with the results obtained from our previous studies,3,4 these findings provide useful hints for improving water models. © 1994 American Chemical Society.