CONICET | Buscador de Institutos y Recursos Humanos

In this article we introduce a simple approach to accurately compute vapor pres-sures from grand canonical molecular dynamics or Monte Carlo simulations. Thisprocedure entails a screening of chemical potentials using a conventional grandcanonical scheme, and therefore it is straightforward to implement for any kindof interface. The scheme is validated against data obtained from Gibbs ensemblesimulations for water and argon. Then, it is applied to obtain the vapor pressureof the coarse-grained mW water model, and it is shown that the computed value isin excellent accord with the one formally deduced using statistical thermodynamicsarguments. Finally, this methodology is used to calculate the vapor pressure of awater nanodroplet of 94 molecules. Interestingly, the result is in perfect agreementwith the one predicted by the Kelvin equation for a homogeneous droplet of that size