Twisting power predictions in a framework of minimalistic atom-atom potentisl approaches.

Chiral molecules dissolved in a nematic phase produce a chiral twisted nematic phase. The ability of a single molecule to twist a nematic phase is quantified by its twisting power. In this presentation, we consider different ways of quantifying the twisting power of chiral molecules by means of calculations based on atom-atom intermolecular potentials that are widely used in quantum chemistry, molecular dynamics calculations, etc. The twisting power calculations are performed in the most minimalistic way but retain the ability to predict the twisting power of real chiral molecules. It is shown that the choice of chiral molecule environment (models for nematic molecules) and averaging of torque exerted on nematic molecules over possible orientations of chiral molecules are crucial for predicting a correct twisting power. The values of twisting power are compared to experimental data for binaphthol molecules and are in good agreement with them. We also consider other chiral "components" of intermolecular interactions (forces, and energies) and discuss their applicability as chirality measures of the chiral molecule. The use of the calculated values as chirality measures of chiral molecules is also considered.