Solute order parameters in liquid crystals from NMR spectra solved with evolutionary algorithms: Application of double Maier-Saupe Kobayashi-McMillan theory

We obtain dipolar couplings via a novel application of evolutionary algorithms solving for multiple spin-systems simultaneously and automatically from the NMR spectra of several solutes in several nematic and smectic liquid crystal solvents. The order parameters obtained from the dipolar couplings are used to test a novel Hamiltonian that includes two Maier-Saupe nematic terms plus Kobayashi-McMillan smectic A terms. It is shown that this Hamiltonian can rationalize the NMR experiments with physically reasonable smectic order parameters and Hamiltonian prefactors. (C) 2009 Elsevier B.V. All rights reserved.