Developing Coarse-Grained Force Fields of Poly (methylmethacrylate-b-2-vinylpyridine) from Atomistic Simulation

2012 ◽  
Vol 562-564 ◽  
pp. 123-128 ◽  
Author(s):  
Bo Du ◽  
Zi Lu Wang ◽  
Xue Hao He
Keyword(s):  
Mechanical Properties ◽  
Force Field ◽  
Self Assembly ◽  
Atomistic Simulation ◽  
Polymer Melts ◽  
Coarse Grained ◽  
Atomistic Simulations ◽  
Inversion Method ◽  
Coarse Grained Model ◽  
Vinyl Pyridine

A coarse-grained force field for poly (methylmethacrylate-b-2-vinyl pyridine) is developed based on the Iterative Boltzmann Inversion method. The proposed coarse-grained model, successfully reproduced the properties of the polymer melts obtained from atomistic simulations, may provide an efficient way to study their mechanical properties and self-assembly behaviors.

scholarly journals Coarse-grained Simulation of Anionic Surfactant Sodium Dodecyl Sulfate

2021 ◽  
Author(s):  
Xiang-feng Jia ◽  
Jing-fei Chen ◽  
Hui-xue Ren ◽  
Qi Wang ◽  
Wen Xu ◽  
...  
Keyword(s):  
Force Field ◽  
Sodium Dodecyl ◽  
Coarse Grained ◽  
Inversion Method ◽  
Ionic Surfactant ◽  
Coarse Grained Model ◽  
Piecewise Function ◽  
Martini Force Field ◽  
Improved Model ◽  
Vdw Interaction

Abstract Through analyzing the deficiency of the current coarse-grained (CG) model, a new CG model for the ionic surfactant was proposed based on the Martini force field and iterative Boltzmann inversion method. In this model, the electrostatic interaction can be tackled by using a self-defined piecewise function to avoid the disadvantage of using coarse-grained solvents, and the VDW interaction parameters were derived by iterative methods. Using the improved model, the radial distribution function of NaCl and SDS solution in all-atom OPLS can be completely reproduced. The successful setup of the new coarse-grained model provides a good example of the construction of a high-precision coarse-grained force field.

scholarly journals Simulations of the 2D self-assembly of tripod-shaped building blocks

2020 ◽  
Vol 11 ◽  
pp. 884-890
Author(s):  
Łukasz Baran ◽  
Wojciech Rżysko ◽  
Edyta Słyk
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Diffraction Pattern ◽  
Triangular Lattice ◽  
Self Assembly ◽  
Building Blocks ◽  
Coarse Grained ◽  
Coarse Grained Model

We introduce a molecular dynamics (MD) coarse-grained model for the description of tripod building blocks. This model has been used by us already for linear, V-shape, and tetratopic molecules. We wanted to further extend its possibilities to trifunctional molecules to prove its versatility. For the chosen systems we have also compared the MD results with Monte Carlo results on a triangular lattice. We have shown that the constraints present in the latter method can enforce the formation of completely different structures, not reproducible with off-lattice simulations. In addition to that, we have characterized the obtained structures regarding various parameters such as theoretical diffraction pattern and average association number.

Length Scale Effects in Materials Deformation of Nano and Microscale Au Structures

2009 ◽  
Author(s):  
Jie Lian ◽  
Junlan Wang
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Size Effect ◽  
Sample Size ◽  
Atomistic Simulation ◽  
Scale Effects ◽  
Elastic Recovery ◽  
Boundary Effect ◽  
Dislocation Nucleation ◽  
Atomistic Simulations

In this study, intrinsic size effect — strong size dependence of mechanical properties — in materials deformation was investigated by performing atomistic simulation of compression on Au (114) pyramids. Sample boundary effect — inaccurate measurement of mechanical properties when sample size is comparable to the indent size — in nanoindentation was also investigated by performing experiments and atomistic simulations of nanoindentation into nano- and micro-scale Au pillars and bulk Au (001) surfaces. For intrinsic size effect, dislocation nucleation and motions that contribute to size effect were analyzed for studying the materials deformation mechanisms. For sample boundary effect, in both experiments and atomistic simulation, the elastic modulus decreases with increasing indent size over sample size ratio. Significantly different dislocation motions contribute to the lower value of the elastic modulus measured in the pillar indentation. The presence of the free surface would allow the dislocations to annihilate, causing a higher elastic recovery during the unloading of pillar indentation.

A Solvent-Mediated Coarse-Grained Model of DNA Derived with the Systematic Newton Inversion Method

2014 ◽  
Vol 10 (8) ◽  
pp. 3541-3549 ◽  
Author(s):  
Aymeric Naômé ◽  
Aatto Laaksonen ◽  
Daniel P. Vercauteren
Keyword(s):  
Coarse Grained ◽  
Inversion Method ◽  
Coarse Grained Model

Dissipative Particle Dynamics Studies on the Self-Assembling Dynamics of the Peptide Amphiphiles

2008 ◽  
Vol 1135 ◽  
Author(s):  
Taiga Seki ◽  
Noriyoshi Arai ◽  
Taku Ozawa ◽  
Tomoko Shimada ◽  
Kenji Yasuoka ◽  
...  
Keyword(s):  
Self Assembly ◽  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
The Self ◽  
Peptide Amphiphiles ◽  
Coarse Grained ◽  
Coarse Grained Model ◽  
Self Assembling ◽  
Micro Structures ◽  
Good Agreement

ABSTRACTA coarse-grained model of peptide amphiphiles (PA) dissolved in aqueous solution was presented, where the effects of PA concentration, temperature and shear stress upon the self-assembly of PA were numerically studied by dissipative particle dynamics (DPD) simulation. We technically investigate the repulsion parameter aHW which indicates the repulsion force between the hydrophilic head of PA and water molecules, hence, at the same time, indicating the change in temperature. It was found that aHW played an important role in the self-assembly dynamics and in the resulting micro-structures of PA. By imposing shear strain on the simulation system, the formation of wormlike PA micelles was accelerated. The simulation results were in good agreement with our previous experimental results and the mechanism of shear-induced transition was proposed.

scholarly journals Structural-Kinetic-Thermodynamic Relationships Identified from Physics-based Molecular Simulation Models

2017 ◽  
Author(s):  
Joseph F. Rudzinski ◽  
Tristan Bereau
Keyword(s):  
Thermodynamic Properties ◽  
Force Field ◽  
Molecular Simulation ◽  
Simulation Models ◽  
Coarse Grained ◽  
Kinetic Properties ◽  
Coarse Grained Model ◽  
Forbidden Configurations ◽  
Force Field Parameters ◽  
Representative System

Coarse-grained molecular simulation models have provided immense, often general, insight into the complex behavior of condensed-phase systems, but suffer from a lost connection to the true dynamical properties of the underlying system. In general, the physics that is built into a model shapes the free-energy landscape, restricting the attainable static and kinetic properties. In this work, we perform a detailed investigation into the property interrelationships resulting from these restrictions, for a representative system of the helix-coil transition. Inspired by high-throughput studies, we systematically vary force-field parameters and monitor their structural, kinetic, and thermodynamic properties. The focus of our investigation is a simple coarse-grained model, which accurately represents the underlying structural ensemble, i.e., effectively avoids sterically-forbidden configurations. As a result of this built-in physics, we observe a rather large restriction in the topology of the networks characterizing the simulation kinetics. When screening across force-field parameters, we find that structurally-accurate models also best reproduce the kinetics, suggesting structural-kinetic relationships for these models. Additionally, an investigation into thermodynamic properties reveals a link between the cooperativity of the transition and the network topology at a single reference temperature.

scholarly journals Interactions Between Nucleosomes: From Atomistic Simulation to Polymer Model

2021 ◽  
Vol 8 ◽  
Author(s):  
Chengwei Zhang ◽  
Jing Huang
Keyword(s):  
Atomistic Simulation ◽  
Umbrella Sampling ◽  
Coarse Grained ◽  
Basic Unit ◽  
Time Dimension ◽  
Effective Interactions ◽  
Coarse Grained Model ◽  
Explicit Solvent ◽  
Chromatin Folding ◽  
Free Energy Landscapes

The organization of genomes in space and time dimension plays an important role in gene expression and regulation. Chromatin folding occurs in a dynamic, structured way that is subject to biophysical rules and biological processes. Nucleosomes are the basic unit of chromatin in living cells, and here we report on the effective interactions between two nucleosomes in physiological conditions using explicit-solvent all-atom simulations. Free energy landscapes derived from umbrella sampling simulations agree well with recent experimental and simulation results. Our simulations reveal the atomistic details of the interactions between nucleosomes in solution and can be used for constructing the coarse-grained model for chromatin in a bottom-up manner.

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