Flexoelectric Coefficients for Model Pear Shaped Molecules from Monte Carlo Simulations

The flexoelectric effect for pear-shaped molecules was studied within NPT Monte Carlo simulations. The asymmetric molecules were modelled by a heterogenic two-site pair potential consisting of rigidly connected Gay-Berne and Lennard-Jones particles, thus giving rise to a steric dipolar moment. The simulation data for order parameters and pair correlation functions were used within a density functional approach to flexoelectric deformations. Due to the locally antisymmetric arrangement of the molecular steric dipoles, the flexoelectric effect turns out to be rather small. In particular, the bend flexoelectric constant is almost vanishing.