Three-dimensional rotational Langevin dynamics and the Lebwohl-Lasher model.

Phys Rev E Stat Nonlin Soft Matter Phys

Groupe de Dynamique des Phases Condensées, Université Montpellier II, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France.

Published: April 2001

We introduce a new scheme for molecular-dynamics simulation of three-dimensional systems exhibiting rotational motions. The procedure is based on the Langevin dynamics method. Our paper is focused on the Lebwohl-Lasher model in order to simulate the isotropic-nematic transition of liquid crystals. In contrast to previous dynamic approximations, our approach allows one to reproduce well the isotropic phase of these systems.

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevE.63.042701DOI Listing

Publication Analysis

Top Keywords

langevin dynamics
8
lebwohl-lasher model
8
three-dimensional rotational
4
rotational langevin
4
dynamics lebwohl-lasher
4
model introduce
4
introduce scheme
4
scheme molecular-dynamics
4
molecular-dynamics simulation
4
simulation three-dimensional
4

Similar Publications

Biomolecules usually adopt ubiquitous circular structures which are important for their functionality. Based on three-dimensional Langevin dynamics simulations, we investigate the conformational change of a polymer confined in a spherical cavity. Both passive and active polymers with either homogeneous or heterogeneous stiffness are analyzed in a comparative manner.

View Article and Find Full Text PDF

The exponential random graph model (ERGM) is a popular model for social networks, which is known to have an intractable likelihood function. Sampling from the posterior for such a model is a long-standing problem in statistical research. We analyze the performance of the stochastic gradient Langevin dynamics (SGLD) algorithm (also known as noisy Longevin Monte Carlo) in tackling this problem, where the stochastic gradient is calculated via running a short Markov chain (the so-called inner Markov chain in this paper) at each iteration.

View Article and Find Full Text PDF

The Role of Light Irradiation and Dendrimer Generation in Directing Electrostatic Self-Assembly.

Polymers (Basel)

January 2025

Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.

pH-responsive polyamidoamine (PAMAM) dendrimers are used as well-defined building blocks to design light-switchable nano-assemblies in solution. The complex interplay between the photoresponsive di-anionic azo dye Acid Yellow 38 (AY38) and the cationic PAMAM dendrimers of different generations is presented in this study. Electrostatic self-assembly involving secondary dipole-dipole interactions provides well-defined assemblies within a broad size range (10 nm-1 μm) with various shapes.

View Article and Find Full Text PDF

A Manufacturing Technique for Binary Clathrate Hydrates for Cold and Very Cold Neutron Production.

Materials (Basel)

January 2025

Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, 38042 Grenoble Cedex 9, France.

Intense sources of very cold neutrons (VCNs) would be beneficial for various neutron scattering techniques and low-energy particle physics experiments. Binary clathrate hydrates hosting deuterated tetrahydrofuran (THF-d) and dioxygen show promise as potential moderators for such sources due to a rich spectrum of localized low-energy excitations of the encaged guest molecules. In this article, we present a reliable manufacturing technique for such hydrates.

View Article and Find Full Text PDF

Positron emission tomography (PET) imaging plays a pivotal role in oncology for the early detection of metastatic tumors and response to therapy assessment due to its high sensitivity compared to anatomical imaging modalities. The balance between image quality and radiation exposure is critical, as reducing the administered dose results in a lower signal-to-noise ratio (SNR) and information loss, which may significantly affect clinical diagnosis. Deep learning (DL) algorithms have recently made significant progress in low-dose (LD) PET reconstruction.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!