Simulating Molecular Properties of Liquid Crystals

Crain, Jason; Komolkin, Andrei V.

doi:10.1002/9780470141687.ch2

Cited by 22 publications

(16 citation statements)

References 159 publications

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“…On the one hand, nCBs are amongst the most-studied and characterized compounds [14] as well as the paradigm of the nematic LC employed in displays. On the other hand, they have also been widely studied theoretically with quantum chemistry [15] and simulation [16][17][18][19][20][21][22][23][24][25][26][27][28][29] methods. It should also be said that nCBs have a rather limited nematic temperature range (4CB is not nematic) and that their transition tempera- We study the important n-cyanobiphenyl (with n = 4-8) series of mesogens, using modelling and molecular dynamics simulations.…”

Section: Introductionmentioning

confidence: 99%

Towards in Silico Liquid Crystals. Realistic Transition Temperatures and Physical Properties for n‐Cyanobiphenyls via Molecular Dynamics Simulations

et al. 2009

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We study the important n-cyanobiphenyl (with n= 4-8) series of mesogens, using modelling and molecular dynamics simulations. We are able to obtain spontaneously ordered nematics upon cooling isotropic samples of 250 molecules. By using the united-atom force field developed herein, we show that the experimental isotropic-nematic transition temperatures are reproduced within 4 K, allowing a molecular-level interpretation of the odd-even effect along the series. Other properties, like densities, orientational order parameters and NMR residual dipolar couplings are also reproduced well, demonstrating the feasibility of predictive in silico modelling of nematics from the molecular structure.

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Section: Introductionmentioning

confidence: 99%

Towards in Silico Liquid Crystals. Realistic Transition Temperatures and Physical Properties for n‐Cyanobiphenyls via Molecular Dynamics Simulations

et al. 2009

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“…In this context, liquid crystalline (LC) materials constitute an excellent test, due to their known sensibility to simulation details as equilibration and production time, sample size and adopted FF (Tiberco et al, private commun.) 3, 5–14. The origin of these requisites lies in the large dimensions of most mesogenic molecules, their slow dynamics and the strong dependence of LC phase stability from the chemical details of their forming molecules 15–18…”

Section: Introductionmentioning

confidence: 99%

Force‐field modeling through quantum mechanical calculations: Molecular dynamics simulations of a nematogenic molecule in its condensed phases

2008

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Interaction energy of the 4-n-pentyloxy-4'-cyanobiphenyl (5OCB) dimer is computed at MP2 level, for many geometrical arrangements using the Fragmentation Reconstruction Method (FRM). DFT calculations are performed for a number of geometries of the monomer. The resulting database is used to parameterize an atomistic intra- and inter-molecular force-field suitable for classical bulk simulations. Several structural and dynamical properties in 5OCB isotropic and liquid crystalline phases are computed from molecular dynamics simulation mainly in the NPT ensemble. Lengthy runs (more than 70 ns) and large sample sizes (up to 806 molecules) were used to determine the nematic to isotropic transition temperature up to a precision of few K. Good agreement was found in most of the investigated properties, thus validating the accuracy of the proposed model potential, only derived by quantum mechanical calculations.

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“…The molecules interact via an anisotropic potential energy which is a function of the relative orientation and location of every pair of molecules. This model system has physical properties [9] consistent with those of real liquid crystalline materials.…”

Section: Introductionmentioning

confidence: 59%

Techniques for the Visualization of Topological Defect Behavior in Nematic Liquid Crystals

Slavin¹,

Pelcovits²,

Loriot³

et al. 2006

IEEE Trans. Visual. Comput. Graphics

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Abstract-We present visualization tools for analyzing molecular simulations of liquid crystal (LC) behavior. The simulation data consists of terabytes of data describing the position and orientation of every molecule in the simulated system over time. Condensed matter physicists study the evolution of topological defects in these data, and our visualization tools focus on that goal. We first convert the discrete simulation data to a sampled version of a continuous second-order tensor field and then use combinations of visualization methods to simultaneously display combinations of contractions of the tensor data, providing an interactive environment for exploring these complicated data. The system, built using AVS, employs colored cutting planes, colored isosurfaces, and colored integral curves to display fields of tensor contractions including Westin's scalar cl, cp, and cs metrics and the principal eigenvector. Our approach has been in active use in the physics lab for over a year. It correctly displays structures already known; it displays the data in a spatially and temporally smoother way than earlier approaches, avoiding confusing grid effects and facilitating the study of multiple time steps; it extends the use of tools developed for visualizing diffusion tensor data, re-interpreting them in the context of molecular simulations; and it has answered long-standing questions regarding the orientation of molecules around defects and the conformational changes of the defects.

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Simulating Molecular Properties of Liquid Crystals

Cited by 22 publications

References 159 publications

Towards in Silico Liquid Crystals. Realistic Transition Temperatures and Physical Properties for n‐Cyanobiphenyls via Molecular Dynamics Simulations

Towards in Silico Liquid Crystals. Realistic Transition Temperatures and Physical Properties for n‐Cyanobiphenyls via Molecular Dynamics Simulations

Force‐field modeling through quantum mechanical calculations: Molecular dynamics simulations of a nematogenic molecule in its condensed phases

Techniques for the Visualization of Topological Defect Behavior in Nematic Liquid Crystals

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