Calculation of liquid-crystal Frank constants by computer simulation

We present the first calculations, by computer simulation, of the Frank elastic constants of a liquid crystal composed of freely rotating and translating molecules. Extensive calculations are performed for hard prolate ellipsoids at a single density, and for hard spherocylinders at three densities. For ellipsoids, the resulting Frank constants are of the same order of magnitude as those found experimentally, and in the expected ratios. For spherocylinders, elastic constants increase rapidly with density. Existing density functional theories are only moderately successful in predicting elastic constants.