Entropy and heat capacity calculations of simulated crystal-hexatic smectic-B-smectic-A liquid-crystal phase transitions.

Entropy and heat capacity are calculated in phase sequence of crystal, hexatic smectic- B , and smectic- A liquid crystals through constant pressure and temperature molecular-dynamics simulations of parallel soft spherocylinders. The transition from crystal to hexatic smectic- B phase is continuous while the transition to smectic- A phase is first order. The dependence of the phase sequence against the molecular shape anisotropy is investigated and there exists a triple point at a rather small anisotropy. Hopping diffusion of molecules is observed in the hexatic smectic- B phase.