First-order nematic-smectic phase transition for hard spherocylinders in the limit of infinite aspect ratio

We report Monte Carlo simulations of the nematic-smectic phase transition for a system of hard spherocylinders with infinite length-to-diameter ratio. A finite-size scaling analysis suggests that this system undergoes a first-order phase transition. When combined with other simulations of the phase behavior of spherocylinders, these results suggest that the nematic-smectic phase transition is first-order for all aspect ratios. This appears to rule out the possibility of a tricritical point predicted by several density-functional theories.