scholarly journals Comparison of the Mesomorphic Behaviour of 1:1 and 1:2 Mixtures of Charged Gay-Berne GB(4.4,20.0,1,1) and Lennard-Jones Particles

Crystals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 371 ◽  
Author(s):  
Tommaso Margola ◽  
Katsuhiko Satoh ◽  
Giacomo Saielli
Keyword(s):  
Honeycomb Structure ◽  
Distribution Functions ◽  
Radial Distribution Functions ◽  
Lennard Jones ◽  
Smectic Phases ◽  
Ionic Liquid Crystals ◽  
The Stability ◽  
Anisotropic Contribution ◽  
A Charge

We present a Molecular Dynamics study of mixtures of charged Gay-Berne (GB) ellipsoids and spherical Lennard-Jones (LJ) particles as models of ionic liquids and ionic liquid crystals. The GB system is highly anisotropic (GB(4.4,20.0,1,1)) and we observe a rich mesomorphism, with ionic nematic and smectic phases in addition to the isotropic mixed phase and crystalline phases with honeycomb structure. The systems have been investigated by analyzing the orientational and translational order parameters, as well as radial distribution functions. We have directly compared 1:1 mixtures, where the GB and LJ particles have a charge equal in magnitude and opposite in sign, and 1:2 mixtures where the number of LJ particles is twice as large compared to the GB and their charge half in magnitude. The results highlight the role of the long-range isotropic electrostatic interaction compared to the short-range van der Waals anisotropic contribution, and the effect of the stoichiometry on the stability of ionic mesophases.

scholarly journals Cholesterol Sequestration by Xenon Leads to Lipid Raft Destabilization

2020 ◽  
Author(s):  
A.D. Reyes-Figueroa ◽  
Mikko Karttunen ◽  
J.C. Ruiz-Suárez
Keyword(s):  
Virial Coefficients ◽  
Md Simulations ◽  
Distribution Functions ◽  
Coarse Grained ◽  
Unexpected Result ◽  
Radial Distribution Functions ◽  
Second Virial Coefficients ◽  
Spontaneous Nucleation ◽  
The Stability ◽  
Anaesthetic Effect

Combined coarse-grained (CG) and atomistic molecular dynamics (MD) simulations were performed to study the interactions of xenon with model lipid rafts consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) and cholesterol (Chol). At a concentration of 2 Xe/lipid we observed an unexpected result: Spontaneous nucleation of Xe nanoclusters which then rapidly plunged into the bilayer. In this process Chol, essential for raft stabilization, was pulled out from the raft into the hydrophobic zone. When concentration was further increased (3 Xe/lipid), the clusters disrupted both the membrane and raft. We computed the radial distribution functions, pair-wise potentials, second virial coefficients and Schlit-ter entropy to scrutinize the nature of the interactions. Our findings suggest that the well-known anaesthetic effect of Xe could be mediated by sequestration of Chol, which, in turn, compromises the stability of rafts where specialized proteins needed to produce the nervous signal are anchored.

Structural properties of amorphous aluminum and aluminum-nitrogen alloys. Computer simulations

2004 ◽  
Vol 848 ◽  
Author(s):  
Ariel A. Valladares ◽  
Alexander Valladares ◽  
R. M. Valladares ◽  
A. Calles
Keyword(s):  
Physical Properties ◽  
Computer Simulations ◽  
First Principles ◽  
Hard Sphere ◽  
Distribution Functions ◽  
Radial Distribution Functions ◽  
Semiconducting Materials ◽  
Atomic Structures ◽  
Lennard Jones ◽  
Nitrogen Alloy

AbstractLiquid and amorphous metallic systems have proven difficult to model. Some efforts have relied on the use of parameterized classical potentials of the Lennard-Jones type or geometric hard sphere simulations, but first principles approaches have been rarely used. Clearly a knowledge of atomic structures is paramount for calculating physical properties. In this work we apply our recently developed ab initio DFT approach (A. A. Valladares et al., Eur. Phys. J. 22 (2001) 443) for the generation of amorphous semiconducting materials, to amorphize aluminum and an aluminum-nitrogen alloy. We report radial distribution functions (RDFs) and specific atomic structures of periodic amorphous/liquid cubic supercells of 108 atoms with a volume of (12.1485 Å)3, generated using the Harris functional.

A coarse-grained model of ionic liquid crystals: the effect of stoichiometry on the stability of the ionic nematic phase

2019 ◽  
Vol 21 (36) ◽  
pp. 20327-20337 ◽  
Author(s):  
Giacomo Saielli ◽  
Katsuhiko Satoh
Keyword(s):  
Ionic Liquid ◽  
Nematic Phase ◽  
Stoichiometric Composition ◽  
Charged Particles ◽  
Coarse Grained ◽  
Thermal Range ◽  
Coarse Grained Model ◽  
Lennard Jones ◽  
Ionic Liquid Crystals ◽  
The Stability

The thermal range of the ionic nematic phase is strongly influenced by the stoichiometric composition of the [GB]n[LJ]msalt in mixtures of Gay-Berne and Lennard-Jones charged-particles.

A Note on the Self Consistent Approximation Method for the Evaluation of Radial Distribution Functions of Simple Fluids

1976 ◽  
Vol 31 (1) ◽  
pp. 31-33 ◽  
Author(s):  
R. V. Gopala Rao ◽  
T. Nammalvar
Keyword(s):  
Radial Distribution ◽  
Approximation Method ◽  
Distribution Functions ◽  
The Self ◽  
Radial Distribution Functions ◽  
Simple Fluids ◽  
Consistent Approximation ◽  
Lennard Jones ◽  
Self Consistent

The self consistent approximation of Rowlinson, Carley and Lado has been applied to calculate the radial distribution functions of simple fluids (Neon, Krypton and Xenon) interacting with a Lennard-Jones 6:12 potential. It has been found that in general the self consistent values are nearer to the exact values than other values.

Sign in / Sign up

Export Citation Format

Share Document