Calculation of the vapour-liquid coexistence curve for a fluctuating point charge water model

Recent studies of the phase behaviour of several polarizable water models have shown that typically the inclusion of polarizability into current non-polarizable, rigid models of water actually decreases the accuracy of their predictions of the liquid-vapour coexistence curve. Most of the polarizable models examined so far have been shown to characteristically over-predict the saturation pressure and correspondingly under-predict the critical temperature. It is the purpose of this Research Note to report the results of a Gibbs—Duhem integration of the liquid—vapour coexistence curve for the TIP4P-FQ water model and to discuss the possible reasons behind the lack of improvement of polarizable water models over their non-polarizable counterparts.