%J Journal of Chemical Physics
%N 21
%V 116
%L discovery1407465
%D 2002
%O Reprinted with permission from Germano, G; Allen, MP; Masters, AJ; (2002) Simultaneous calculation of the helical pitch and the twist elastic constant in chiral liquid crystals from intermolecular torques. Journal of Chemical Physics, 116 (21) pp. 9422-9430. 10.1063/1.1475747. Copyright 2002, American Institute of Physics.
%T Simultaneous calculation of the helical pitch and the twist elastic constant in chiral liquid crystals from intermolecular torques
%A G Germano
%A MP Allen
%A AJ Masters
%X We present a molecular simulation method that yields simultaneously the equilibrium pitch wave
number q and the twist elastic constant K2 of a chiral nematic liquid crystal by sampling the torque
density. A simulation of an untwisted system in periodic boundary conditions gives the product K2q;
a further simulation with a uniform twist applied provides enough information to separately
determine the two factors. We test our new method for a model potential, comparing the results with
K2q from a thermodynamic integration route, and with K2 from an order fluctuation analysis. We
also present a thermodynamic perturbation theory analysis valid in the limit of weak chirality.
%P 9422-9430