@article {2526,
	title = {Evolutionary algorithms to solve complicated NMR spectra},
	journal = {Journal of Chemical Physics},
	volume = {130},
	number = {4},
	year = {2009},
	note = {ISI Document Delivery No.: 401TJTimes Cited: 3Cited Reference Count: 37Meerts, W. Leo de Lange, C. A. Weber, A. C. J. Burnell, E. E.},
	month = {Jan},
	pages = {8},
	type = {Article},
	abstract = {The complexity of H-1 NMR spectra of solutes in partially ordered solvents such as liquid crystals increases rapidly with the number of spins. Spectra of simple solutes with sufficient symmetry and containing not too many spins (typically <= 8) are readily analyzed. The analysis of larger spin systems is more difficult, and often impossible. In this paper we present the application of a general automated evolutionary algorithm to solve the highly complex proton NMR spectrum of the 12-spin system pentane, a solute that interconverts rapidly among several symmetry-unrelated conformations. The interpretation of the spectral parameters that are obtained from the analysis requires the use of a model to connect relative orientational orders in symmetry-unrelated conformers.},
	keywords = {ALKYL CHAINS, AUTOMATED-ANALYSIS, evolutionary computation, HIGH-RESOLUTION NMR, liquid crystals, magnetic resonance, MOLECULAR-STRUCTURE, MULTIPLE-QUANTUM SPECTRA, NEMATIC LIQUID-CRYSTALS, ORDER, organic compounds, PROTON, SHAPE, SOLUTES, spectroscopy computing, STRATEGY},
	isbn = {0021-9606},
	url = {<Go to ISI>://000262965000028},
	author = {Meerts, W. L. and de Lange, C. A. and Weber, A. C. J. and Burnell, E. E.}
}
@article {2399,
	title = {Orientational order of near D-3h solutes in nematic liquid crystals},
	journal = {Journal of Chemical Physics},
	volume = {130},
	number = {15},
	year = {2009},
	note = {ISI Document Delivery No.: 437KLTimes Cited: 2Cited Reference Count: 49Danilovic, Zorana Burnell, E. Elliott},
	month = {Apr},
	pages = {11},
	type = {Article},
	abstract = {Solutes that are similar in size, have a shape that is close to D-3h symmetry but contain dissimilar substituent groups (methyl versus chloro, contributing different electrostatic interactions to the anisotropic intermolecular potential), are used to delineate the short- and long-range anisotropic intermolecular interactions that lead to solute orientational order in nematic liquid crystals. The short-range interactions should be similar for all solutes and for D-3h symmetry should yield a single independent order parameter, whereas the long-range interactions are expected to differ with solute. Short-range size and shape mechanisms account for solute orientational order measured in magic mixtures (e.g., 55 wt \% ZLI-1132/N-p-ethoxybenzylidene-p({\textquoteright})-n-butylaniline), whereas additional mechanisms are required in other nematic liquid-crystal solvents. The results obtained for long-range interactions cannot be rationalized in detail using simple mean-field models that incorporate solute dipoles, quadrupoles, or polarizabilities. The results suggest that details of the solute electrostatics may need to be incorporated into the description of the anisotropic intermolecular potential.},
	keywords = {AB-INITIO, ELECTRIC-FIELD GRADIENT, electrostatic, interactions, liquid crystals, LIQUID MIXTURES, liquid structure, MEAN TORQUE, molecular orientation, MOLECULAR-HYDROGEN, MONTE-CARLO SIMULATIONS, nematic, NMR, polarisability, POTENTIALS, SHAPE, SOLVENTS},
	isbn = {0021-9606},
	url = {<Go to ISI>://000265486300032},
	author = {Danilovic, Z. and Burnell, E. E.}
}
@article {2615,
	title = {Orientational order of near D-3h solutes in nematic liquid crystals. II. Description via Gay-Berne model with embedded quadrupoles},
	journal = {Journal of Chemical Physics},
	volume = {130},
	number = {15},
	year = {2009},
	note = {ISI Document Delivery No.: 437KLTimes Cited: 3Cited Reference Count: 19Sokolovskii, R. O. Burnell, E. Elliott},
	month = {Apr},
	pages = {6},
	type = {Article},
	abstract = {We perform Monte Carlo simulations of a mixture of soft ellipsoids with embedded quadrupoles as a model of various chloro- and methyl-substituted benzenes dissolved in nematic liquid crystals. We find that oblate Gay-Berne ellipsoids with multiple embedded quadrupoles qualitatively reproduce the trend in the order parameter asymmetry experimentally observed in NMR spectra. The trend is opposite to what is expected on the basis of the interaction of the solute{\textquoteright}s quadrupole with the solvent{\textquoteright}s average electric field gradient "felt" by dissolved dihydrogen molecules. We identify the specific minimum of the solute-solvent interaction energy landscape that may produce the unexpected sign of the order parameter asymmetry that is seen in the experiment and the simulation.},
	keywords = {COMPOUNDS, deuterium, dissolving, ELECTRIC-DIPOLE INTERACTIONS, LIQUID MIXTURES, liquid theory, METHODS, Monte Carlo, MONTE-CARLO SIMULATIONS, nematic liquid crystals, nuclear magnetic resonance, ORGANIC, POTENTIALS, SHAPE, SOLVENTS},
	isbn = {0021-9606},
	url = {<Go to ISI>://000265486300033},
	author = {Sokolovskii, R. O. and Burnell, E. E.}
}
@article {2656,
	title = {Solute order parameters in liquid crystals from NMR spectra solved with evolutionary algorithms: Application of double Maier-Saupe Kobayashi-McMillan theory},
	journal = {Chemical Physics Letters},
	volume = {476},
	number = {1-3},
	year = {2009},
	note = {ISI Document Delivery No.: 463YQTimes Cited: 2Cited Reference Count: 25Weber, Adrian C. J. Yang, Xuan Dong, Ronald Y. Meerts, W. Leo Burnell, E. Elliott},
	month = {Jul},
	pages = {116-119},
	type = {Article},
	abstract = {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.},
	keywords = {ELECTRON-DIFFRACTION, MOLECULAR-STRUCTURES, NEMATIC SOLVENTS, orientational order, PHASE, SHAPE},
	isbn = {0009-2614},
	url = {<Go to ISI>://000267470600025},
	author = {Weber, A. C. J. and Yang, X. and Dong, R. Y. and Meerts, W. L. and Burnell, E. E.}
}
@article {1044,
	title = {NMR measurement of smectic ordering and nematic-smectic-A coupling in a liquid crystal},
	journal = {Chemical Physics Letters},
	volume = {398},
	number = {4-6},
	year = {2004},
	note = {ISI Document Delivery No.: 867OVTimes Cited: 11Cited Reference Count: 31},
	month = {Nov},
	pages = {517-521},
	type = {Article},
	abstract = {The nuclear magnetic resonance (NMR) spectra of three substituted benzenes as solutes in the liquid crystal 8CB were investigated. The orientational order of all solutes was obtained in the nematic and smectic-A phases. A change in temperature dependence of orientational ordering was observed at the nematic to smectic-A phase transition. We analyzed these results via Kobayashi-McMillan theory applied to solutes, i.e. by incorporating smectic-A layering and nematic smectic-A coupling into a mean-field orientational Hamiltonian. By fitting to experiment, we fully determined Hamiltonian prefactors. The nematic smectic coupling, determined for the first time by NMR, appears solute independent. Solute smectic-A order parameters were self-consistently determined. (C) 2004 Published by Elsevier B.V.},
	keywords = {BINARY-MIXTURES, FIELD, NUCLEAR-MAGNETIC-RESONANCE, orientational order, PHASE-TRANSITION, SHAPE, SOLUTES, TEMPERATURE-DEPENDENCE, TRICRITICAL POINT},
	isbn = {0009-2614},
	url = {<Go to ISI>://000224852800044},
	author = {Yethiraj, A. and Sun, Z. M. and Dong, R. Y. and Burnell, E. E.}
}
@article {515,
	title = {Effects of solute properties and concentrations on liquid crystals: N-(4-ethoxybenzylidene)-2,6-dideutero-4-n-butylaniline},
	journal = {Journal of Chemical Physics},
	volume = {117},
	number = {1},
	year = {2002},
	note = {ISI Document Delivery No.: 563UTTimes Cited: 4Cited Reference Count: 17},
	month = {Jul},
	pages = {376-384},
	type = {Article},
	abstract = {The effects of the nature and concentration of the solutes 1,3,5-trichlorobenzene (TCB), benzene, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, and p-dichlorobenzene on orientational order in the nematic liquid crystal N-(4-ethoxybenzylidene)-2,6-dideutero-4-n-butylaniline are investigated using NMR spectroscopy. Seven separate samples containing differing concentrations of all solutes are investigated at constant temperature, at constant reduced temperature, at constant TCB orientational order, and at constant liquid crystal orientational order. Various schemes for comparison of orientational order among the samples are examined. For the experiments performed here, the most consistent method to compare solute orientational order in the different samples is to multiply results from the experiments performed at constant temperature by the factor needed to equate the TCB order parameters. (C) 2002 American Institute of Physics.},
	keywords = {MULTIPLE-QUANTUM NMR, orientational order, SHAPE, SHORT-RANGE},
	isbn = {0021-9606},
	url = {<Go to ISI>://000176275700046},
	author = {Syvitski, R. T. and Pau, M. Y. M. and Burnell, E. E.}
}
@article {4746,
	title = {Monte Carlo simulations of zero electric field gradient liquid crystal mixtures},
	journal = {Chemical Physics Letters},
	volume = {331},
	number = {5-6},
	year = {2000},
	note = {ISI Document Delivery No.: 382YCTimes Cited: 13Cited Reference Count: 14},
	month = {Dec},
	pages = {455-464},
	type = {Article},
	abstract = {We explore with Monte Carlo simulations the NMR finding that solutes in special nematic liquid crystal mixtures {\textquoteright}feel{\textquoteright} zero average electric field gradient F-ZZ. The simulations involve solute-solvent mixtures of 1000 identical Gay-Berne ellipsoidal particles with added electric quadrupoles of varying strengths placed at particle centres. As long as all quadrupoles are sufficiently small, F-ZZ calculated at the particle centres is equal for all particles. For larger quadrupole moments, interactions among quadrupoles alter the interparticle distribution and subsequently F-ZZ depends on both solvent and solute quadrupoles; in general, the quadrupolar interactions produce a negative contribution to energy. (C) 2000 Elsevier Science B.V. All rights reserved.},
	keywords = {NMR, orientational order, SHAPE, SOLUTES},
	isbn = {0009-2614},
	url = {<Go to ISI>://000165854100016},
	author = {Burnell, E. E. and Berardi, R. and Syvitski, R. T. and Zannoni, C.}
}
@article {4677,
	title = {Intermolecular potentials in liquid crystals: Comparison between simulations and NMR experiments},
	journal = {International Journal of Modern Physics C},
	volume = {10},
	number = {2-3},
	year = {1999},
	note = {ISI Document Delivery No.: 222HPTimes Cited: 12Cited Reference Count: 21Meeting on Recent Developments in the Computer Simulations of Liquid CrystalsJUN 18, 1998ERICE, ITALY},
	month = {May},
	pages = {403-413},
	type = {Proceedings Paper},
	abstract = {The anisotropic intermolecular forces responsible for the orientational ordering in liquid crystals are probed by comparing Monte Carlo (MC) simulations with experimental nuclear magnetic resonance (NMR) results for solutes in nematic liquid crystals. In a special liquid crystal mixture where all long-range interactions are assumed to be minimized, the models for short-range interactions which best fit NMR experimental solute order parameters also best fit solute order parameters from MC simulations of hard ellipsoids. This is taken as an indication that in this special mixture the intermolecular potential is dominated by short-range forces. However, for liquid crystals where long-range interactions are important, simulations of hard ellipsoids with point quadrupoles cannot reproduce even the gross effects observed with experimental NMR data.},
	keywords = {anisotropic intermolecular force, ELECTRIC-DIPOLE INTERACTIONS, interaction, liquid crystal, MOLECULES, Monte Carlo, MONTE-CARLO SIMULATIONS, NEMATIC SOLVENTS, nuclear magnetic resonance experiment, ORDER, ORIENTATIONAL, quadrupole interaction, SHAPE, SHORT-RANGE, SIMULATION, SIZE, SOLUTES},
	isbn = {0129-1831},
	url = {<Go to ISI>://000081779000007},
	author = {Syvitski, R. T. and Polson, J. M. and Burnell, E. E.}
}
@article {4114,
	title = {Analysis of single and multiple quantum NMR spectra of 1,3-dichloro-2-ethenylbenzene in liquid crystal solvents},
	journal = {Molecular Physics},
	volume = {90},
	number = {4},
	year = {1997},
	note = {ISI Document Delivery No.: WN909Times Cited: 10Cited Reference Count: 37},
	month = {Mar},
	pages = {541-551},
	type = {Article},
	abstract = {The single and multiple quantum NMR spectra of 1,3-dichloro-2-ethenylbenzene as solute in two different nematic liquid crystals have been measured and analysed in terms of dipolar couplings and chemical shift differences. Because the single quantum spectra did not yield to straightforward analysis, normal and frequency selective multiple quantum experiments were used to aid the analysis. The results from four spectra were combined to yield structural information and the order matrix in each solution. The structure of the ring is very close to that of 1,3-dichlorobenzene, and that of the ethenyl group very close to that of ethenyl-benzene. The dihedral angle between the ethenyl group and the aromatic ring is found to be 454 +/- 1.0 degrees, and the C-CC=C angle is found to be 127.3 +/- 0.3 degrees.},
	keywords = {EQUILIBRIUM, FIELD, MAGNETIC-RESONANCE, MIXTURES, MOLECULAR-STRUCTURE, orientational order, ROTATION, SHAPE, SOLUTES, SPECTROSCOPY},
	isbn = {0026-8976},
	url = {<Go to ISI>://A1997WN90900005},
	author = {Rendell, J. C. T. and Burnell, E. E.}
}
@article {4115,
	title = {Orientational order of 1,3-dichloro-2-ethenylbenzene in liquid crystal solvents},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {75},
	number = {8},
	year = {1997},
	note = {ISI Document Delivery No.: XX043Times Cited: 2Cited Reference Count: 38},
	month = {Aug},
	pages = {1156-1161},
	type = {Article},
	abstract = {The order parameter matrices of a molecule that has no symmetry, 1,3-dichloro-2-ethenylbenzene, dissolved in two different nematic liquid-crystal solvents are analyzed in terms of various models for the intermolecular mean-field potential. In a mixture of liquid crystals for which the interaction between the molecular quadrupole moment tensor and the average electric field gradient of the nematic solvent has been minimized, the orientational order is best described by models for the short-range anisotropic potential. The most successful potentials are written in terms of anisotropic interactions between the solute surface and the liquid-crystal mean field. This represents a strong test of such models because they simultaneously fit the five independent orientational parameters obtained from the same solute, thus removing the problems associated with comparing results among different solutes in either the same or a different sample tube.},
	keywords = {ALKYL CHAINS, ANISOTROPIC, FIELD, INTERMOLECULAR FORCES, liquid crystals, MAGNETIC-RESONANCE, MIXTURES, MOLECULES, NEMATIC SOLVENT, NMR, order parameters, PHASES, SHAPE, SOLUTES},
	isbn = {0008-4042},
	url = {<Go to ISI>://A1997XX04300014},
	author = {Rendell, J. C. T. and Zimmerman, D. S. and vanderEst, A. J. and Burnell, E. E.}
}
@article {3930,
	title = {A temperature dependence study of small solutes in zero electric field gradient nematic liquid crystal mixtures},
	journal = {Molecular Physics},
	volume = {90},
	number = {3},
	year = {1997},
	note = {ISI Document Delivery No.: WK754Times Cited: 10Cited Reference Count: 50},
	month = {Feb},
	pages = {303-313},
	type = {Article},
	abstract = {The temperature dependences of the proton nuclear magnetic resonance (NMR) spectra of the solutes 1,3,5-trichlorobenzene, metadichlorobenzene, orthodichlorobenzene, 1,3-bromochlorobenzene, benzene and 2-butyne have been studied in the special {\textquoteright}zero electric field gradient{\textquoteright} mixtures 55wt\% 1132-N-(4-ethoxybenzylidene)-4{\textquoteright}-n-butylaniline (EBBA) and 70wt\% (4-n-pentyl)-4{\textquoteright}-cyanobiphenyl-EBBA. The order parameter matrices obtained for each solute from an analysis of the NMR spectra indicate that the solutes experience a similar anisotropic potential in both mixtures.},
	keywords = {BIAXIAL SOLUTE, CONFORMATIONAL EQUILIBRIUM, INTERNAL-ROTATION, MOLECULES, NORMAL-BUTANE, orientational order, POTENTIAL FUNCTION, RAMAN-SPECTRA, SHAPE, SOLVENTS},
	isbn = {0026-8976},
	url = {<Go to ISI>://A1997WK75400001},
	author = {Chandrakumar, T. and Burnell, E. E.}
}
@article {3270,
	title = {AN ORIENTATIONAL STUDY OF SMALL SOLUTES IN ZERO ELECTRIC-FIELD GRADIENT NEMATIC LIQUID-CRYSTAL MIXTURES},
	journal = {Journal of Physical Chemistry},
	volume = {99},
	number = {18},
	year = {1995},
	note = {ISI Document Delivery No.: QW705Times Cited: 2Cited Reference Count: 32},
	month = {May},
	pages = {7054-7059},
	type = {Article},
	abstract = {The solutes m-dichlorobenzene, o-dichlorobenzene. p-dichlorobenzene, o-dicyanzene, furan, tetrathiofulvalene, and fluorobenzene are studied in the zero electric field gradient mixtures 56.5 wt \% 1132/EBBA and 70 wt \% 5CB/EBBA using proton NMR. The two second-rank-order parameters obtained for each solute from analysis of the NMR spectra indicate that the solutes experience a similar anisotropic potential in both mixtures. The results are interpreted in terms of two models for the short-range anisotropic potential experienced by the solutes.},
	keywords = {ALKYL CHAINS, BEHAVIOR, DIPOLE INTERACTIONS, MEAN TORQUE, MOLECULES, PHASE, POTENTIALS, SHAPE, SIZE, SOLVENTS},
	isbn = {0022-3654},
	url = {<Go to ISI>://A1995QW70500043},
	author = {Chandrakumar, T. and Smith, L. and Burnell, E. E.}
}
@article {7109,
	title = {COMPARISON OF WKB (WENTZEL-KRAMERS-BRILLOUIN) AND SWKB SOLUTIONS OF FOKKER-PLANCK EQUATIONS WITH EXACT RESULTS - APPLICATION TO ELECTRON THERMALIZATION},
	journal = {Canadian Journal of Physics},
	volume = {69},
	number = {6},
	year = {1991},
	note = {ISI Document Delivery No.: FZ294Times Cited: 5Cited Reference Count: 41},
	month = {Jun},
	pages = {712-719},
	type = {Article},
	abstract = {A comparison of WKB (Wentzel-Kramers-Brillouin) and SWKB eigenfunctions of the Schrodinger equation for potentials in the class encountered in supersymmetric quantum mechanics is presented. The potentials that are studied are those that result from the transformation of a Fokker-Planck eigenvalue problem to a Schrodinger equation. Linear Fokker-Planck equations of the type considered in this paper give the probability distribution function for a large number of physical situations. The time-dependent solutions can be expressed as a sum of exponential terms with each term characterized by an eigenvalue of the Fokker-Planck operator. The specific Fokker-Planck operator considered is the one that describes the thermalization of electrons in the inert gases. The WKB and SWKB semiclassical approximations are compared with exact numerical results. Although the eigenvalues can be very close to the exact values, we find significant departures for the eigenfunctions.},
	keywords = {ACTIVATED, APPROXIMATION, DISCRETE-ORDINATE METHOD, EIGENVALUES, INVARIANCE, ISOMERIZATION, NUCLEATION, RARE-GAS MODERATORS, RATE-PROCESSES, SHAPE, SOLVABLE POTENTIALS, SUPERSYMMETRIC QUANTUM-MECHANICS},
	isbn = {0008-4204},
	url = {<Go to ISI>://A1991FZ29400011},
	author = {Shizgal, B. and Demeio, L.}
}
