Overcoming the Barrier on Time Step Size in Multiscale Molecular Dynamics Simulation of Molecular Liquids

2011 ◽  
Vol 8 (1) ◽  
pp. 6-16 ◽  
Author(s):  
Igor P. Omelyan ◽  
Andriy Kovalenko
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Molecular Liquids ◽  
Step Size ◽  
Time Step ◽  
Time Step Size

Investigation of Fractional Characteristic of Molecular Motion by Molecular Dynamics Simulation

2004 ◽  
Author(s):  
Chao Liu ◽  
Liming Wan ◽  
Xinming Zhang ◽  
Danling Zeng
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Vapor Phase ◽  
Molecular Motion ◽  
Mean Free Path ◽  
Dynamics Simulation ◽  
Fractional Dimension ◽  
Time Step ◽  
Vapor Interface ◽  
Liquid Vapor

Molecular dynamics simulation (MDS) is adopted to investigate the characteristic of fractional motion of molecules in liquid phase, vapor phase and liquid-vapor interface in the paper. Based on the theory of mean free path and Shannon sampling theorem, the way to determine a universal criterion of time step of simulation is presented. It is shown that there exists difference in the regular pattern of molecular motion in the state of liquid and vapor phase. The fractional features are different for different matter states. Under the condition of same temperature, the characteristic fractional number of molecular motion in liquid state is greater than one in vapor state. It is shown that the fractional dimension numbers in the X, Y and Z direction of the liquid-vapor interface are different. This proves that the liquid-vapor interface has anisotropic character.

The Recent Developments of Molecular Dynamics Simulation

2013 ◽  
Vol 444-445 ◽  
pp. 1370-1373
Author(s):  
Wen Hai Gai ◽  
Ran Guo ◽  
Yuan Yuan Liu
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Rapid Development ◽  
Equations Of Motion ◽  
Dynamics Simulation ◽  
Impact Factors ◽  
Lagrange Equations ◽  
Time Step ◽  
Basic Principles ◽  
Recent Developments

Based on the development of nanomaterials and the research on performance parameters of materials, molecular dynamics simulation has been rapid development and application. It is widely found that the material's physical, mechanical and other properties are both closely related to its macroscopic state and microstructure [. In order to explore and understand the nature of the material properties we need to analyze various impact factors including macroscopic, mesoscopic and microscopic. This paper describes the basic concepts and methods of molecular dynamics. The contents are comprised of time step, formulas such as Lagrange equations of motion and Hamiltonian equations of motion. The basic principles and recent developments of molecular dynamics were reviewed.

scholarly journals Variable time domain discretization methodology for molecular dynamics simulation of metallic compounds

2021 ◽  
Author(s):  
Jamal Zeinalov
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Potential Energy ◽  
Molecular Dynamics Simulations ◽  
Dynamics Simulation ◽  
Time Step ◽  
Variable Time ◽  
Metallic Compounds ◽  
Dynamics Simulations ◽  
Computational Resources

The present work proposes a methodology to improve the computational requirements of molecular dynamics simulations while maintaining or improving the fidelity of the obtained results. The most common method of molecular dynamics simulation at present is the multi-force, constant time-step, explicit computation, which advances a single time step at a time to determine the next state of the system. The present work proposes a variable time-step strategy, where a single large simulation is subdivided into multiple time domains which redistribute computational resources where they are needed the most: in areas of higher than average potential or kinetic energy or highly dynamic areas around impurity clusters, void formations and crack propagations. The research focuses on the simulation of metallic compounds, as these form the basis of most common molecular dynamics simulations, and have been very thoroughly investigated over the years, thus providing a very extensive body of work for the purpose of comparison and validation of the proposed methodology. The novel methodology presented in this work allows to alleviate some of the limitations associated with the molecular dynamics methodologies and go beyond traditional scales of simulation. The proposed method has been observed to deliver 5 to 20 percent increase in simulation size domain while maintaining or improving the accuracy and computational cycle time. The benefits were observed to be greater for large simulations with one or more areas of higher than average kinetic or potential energy levels, such as those found during crack initiation and propagation, coating-substrate interface, localized pressure application or large thermal gradient. The large difference allows for very clear prioritization of computational resources for high energy areas and as a result provides for faster and more accurate simulation even with increased domain size. Conversely, this method has been observed to provide little to no benefit when simulating stable systems that are undergoing very slow change, such as (relatively) slow change in ambient temperature or pressure, or otherwise homogeneous internal and external boundary conditions. However, for the majority of applications described above, including coating deposition and additive manufacturing, the proposed methodology will yield substantial increase in both simulation size and accuracy, since in the aforementioned processes kinetic and potential energy gradients across the simulation are typically very significant

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