Molecular dynamics simulation of water CCl4 mixtures

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Abstract
A computer simulation of the molecular dynamics of a mixture of water and CCl4 molecules has been carried out with site–site terms for the intermolecular potentials. These are made up of Lennard‐Jones interactions for the atom–atom terms and partial charges for the electrostatics. In a subpicosecond interval of time the H bonding structure of the pure aqueous environment is disrupted by the more massive CCl4 molecules; both in a 50% and 11% n/n emulsion. In this time interval the fine emulsion of water molecules in carbon tetrachloride has not had time to separate into water and carbon tetrachloride layers as would be expected from the immiscibility of the two macroscopic liquids. Therefore, the simulation provides a means of studying in detail the dynamics of water molecules freed of hydrogen bonding in an environment of much more massive carbon tetrachloride molecules. This provides an opportunity of investigating the effect of H bonding on the atom–atom pair distribution functions and time correlation functions of the dynamical ensemble. The most pronounced effect of distributing the water molecules in this way is seen in single molecule cross correlation such as 〈v(t)ωT(0)〉 where v is the linear molecular center‐of‐mass velocity and ω the angular velocity of the same molecule.