Suitability of the kihara potential to predict molecular spectra of linear polyatomic liquids

Gibbs ensemble Monte Carlo (GEMC) simulations of linear molecular liquid chlorine and carbon disulfide are performed to determine the vapor-liquid equilibrium (VLE) of these fluids and the corresponding intermolecular potential parameters. The intermolecular potential function considered is the Kihara potential with a point multipole added. Molecular dynamics runs of liquid nitrous oxide, chlorine, and carbon disulfide are then presented to obtain angular velocity autocorrelation functions of different orders. Using these functions, transport coefficients as well as correlation times are calculated. Next, the band shapes of molecular vibration spectra are obtained as Fourier transforms of the autocorrelation functions. Agreement between experiment and simulation is excellent for all the calculated properties of chlorine, showing that the intermolecular potential presented here is extremely accurate as well as simple. Results for carbon disulfide and nitrous oxide range from very good to acceptable for different correlation times and transport properties and they are discussed in detail in the text.