We perform an extensive computational study on the phase behavior of hard banana-shaped particles, and show that biaxial, twist-bend, and splay-bend nematic phases are metastable with respect to a smectic phase for a system of hard bent spherocylinders. However, if the smectic phase is destabilized—either by polydispersity in the particle length or by curvature in the particle shape—stable biaxial, twist-bend, and splay-bend nematic phases are obtained. This provides a unified and consistent picture on the subtle role of particle shape on the phase behavior of bent rods.

• Received 11 March 2019
• Revised 20 June 2019

DOI:https://doi.org/10.1103/PhysRevLett.123.068001