Local structure and orientational correlations in fluids composed of linear triatomic molecules

The local structure and orientational correlations in a fluid of linear tangent-hard-sphere triatomics are investigated via Monte Carlo simulation and various liquid state theories. Of the theories tested, the perturbation density functional theory of Kierlik and Rosinberg and the integral equation theory of Richardson and Chandler are found to be the most accurate for the site-site pair correlation functions. However, none of the theories is able to describe correctly the degree of orientational order observed in the simulations.