We report Monte Carlo simulations of a system of rigid zigzag-shaped molecules that demonstrate that simple excluded-volume interactions are sufficient to produce a fluid tilted lamellar [smectic $C$ ($\mathrm{S}\mathrm{m}C$)] liquid crystal phase. The molecules are composed of three rigidly linked hard spherocylinders arranged in a zigzag fashion. By varying the zigzag angle we have mapped out the whole phase diagram as a function of pressure and zigzag angle $\Psi$. For $\Psi$ between $35°$ and $80°$ our model simulation exhibits the $\mathrm{S}\mathrm{m}C$ phase. This is the first conclusive evidence where steric interactions arising out of molecular shape alone induce the occurrence of the $\mathrm{S}\mathrm{m}C$ phase for a wide range of zigzag angles. For smaller $\Psi$, a transition from tilted crystal to crystal is observed.

• Received 22 July 2003

DOI:https://doi.org/10.1103/PhysRevLett.92.025501