Local structure of tangent-hard-sphere diatomic fluids

Abstract

The local structure of tangent hard sphere diatomics is investigated via the reference interaction site model (RISM) integral equation theory of Chandler and Anderson and the diagramatically proper theory of Chandler, Silbey, and Ladanyi (CSL). A comparison with Monte Carlo simulation data shows that, in contrast to previous investigations of Lennard-Jones diatomics, the CSL theory is very accurate for g(r) over the entire range of fluid densities, and performs much better than the RISM theory, especially at low densities. The CSL theory is also more accurate than RISM (when compared with simulations) for the compressibility equation of state.