A 2-Site Model for Simulating Supercritical Fluoroform

A 2-site model of fluoroform (CHF 3 ) has been developed for use in simulations of solvation in the near critical regime. The model was optimized to reproduce the critical point and the liquid−vapor coexistence curve of the real fluid using the Gibbs Ensemble Monte Carlo method. Additional Monte Carlo and molecular dynamics simulations demonstrate that this simplified model also reproduces a number of other properties of CHF 3 relevant to its use in simulations of solvation and reaction. Along a near critical isotherm, vapor pressures, dielectric constants, self-diffusion coefficients, and viscosities are all found to be within 15% of experimental values. The main shortcoming of the model appears to be in its representation of the rotational dynamics of CHF 3 molecules, which are faster in the model compared to the real fluid by ∼25% at near and above the critical density.