Computer simulation of the supercritical carbon dioxide fluid (II) internal energy and structure of carbon dioxide system containing one benzene molecule

Using potential models based on ab initio quantum chemical calculations, we study a supercritical CO2 fluid containing one benzene molecule using Monte Carlo simulations. First, molecular average internal energy is calculated for the whole system and for the first solvation shell of the benzene molecule. This analysis shows that the CO2 molecules in the first solvation shell have a large energetic stabilization owing to the shape of the solute. In addition to the stabilization, the solute-solvent interactions in the first solvation shell show large fluctuations for both the in-plane and out-of-plane parts. Secondly, an orientational distribution function is defined to investigate the CO2 fluid structure. This function indicates that the CO2CO2 intermolecular configuration has a large dependence on the temperature of the system for both the whole system, and for the first solvation shell of the solute. Moreover, the benzene molecule is confirmed to control the mutual arrangement between neighboring CO2 molecules.