Molecular theoretical calculations on temperature dependence of the pitch of cholesteric liquid crystals

The temperature-dependent pitch of a cholesteric phase is studied using both molecular field theory and the two-particle cluster theory. The interacting chiral molecules (as derived by van der Meer et al.) are placed at the sites of a three-dimensional, simple cubic lattice with orientations confined to two dimensions. The equilibrium pitch as functions of temperature is calculated and numerical results are compared with those predicted by Monte Carlo computer simulation. The two-particle cluster theory, taking into account short-range correlations between molecules, yields improved values compared with molecular field theory.