Density and energy distribution in water and organic solvents: A molecular dynamics study

The density fluctuations in simulated neat water, methanol and acetone are studied from the radial and site-site distribution functions, as well as the corresponding energy distribution functions. The comparison of the running integrals of these two quantities allows elucidating the peculiarities of each system in what concerns the influence of the local hydrogen bonding on the microheterogeneity of the system. It is shown that the correlations beyond the first neighbours reproduce accurately the density fluctuations, despite the constant-N simulation constraint, and match the experimental value for all models and systems studied herein.