Validity of Molecular Dynamics for the Simulation of Soft Matter

25th IUPAP Conference on Computational Physics

物理学;计算机科学

Kim, Sangrak^1

Department of Physics, Kyonggi University, 154-42 Gwangyosanro, Youngtong-ku, Suwon 440-760, Korea, Republic of^1

关键词: Broken power law;    Infinite numbers;    Molecular dynamics simulations;    One-dimensional systems;    Piecewise-continuous;    Power-law behavior;    Repulsive potentials;    Uniform distribution;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/510/1/012040/pdf
DOI  :  10.1088/1742-6596/510/1/012040

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

We examine the validity of molecular dynamics simulations for a simple one-dimensional system having a piecewise continuous linear repulsive potential wall with a constant slope a. The inevitable energy change ΔE that occurs in the collision with the potential wall is shown to be dependent on only two parameters α and μ ≡ aτ/p0, where α is a fraction of the time step τ immediately after the contact with the potential wall and p0 is the momentum just before the collision. The whole space of parameters α and μ can be divided into an infinite number of regions, where each region generates separately a positive or negative energy change ΔE. The envelope of |ΔE| shows a power law behavior |ΔE| μβwith the exponent β 1.08. The average of |ΔE|α over a uniform distribution of α shows a broken power law behavior |ΔE|α μβwith β 1.98 at larger μ values and β 0.99 at smaller μ values.