Calculating the hopping times of confined fluids: two hard disks in a box.
Calculating the hopping times of confined fluids: two hard disks in a box.
复制标题
计算密闭流体的跳跃时间：一个盒子里的两个硬盘。
DOI：
10.1063/1.1811075
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发表时间：
2004
影响因子：
4.4
通讯作者：
J. Percus
中科院分区：
文献类型：
--
作者：
R. Bowles;K. K. Mon;J. Percus
高度受限流体的异常单列扩散和体正常扩散之间的动力学转变可以通过涉及粒子跳跃时间τ（hop）的唯象模型来描述。我们提出了一个理论的形式主义，这将是有用的计算tau（跳）的各种系统和测试它使用一个简单的模型组成的两个硬盘局限于一个矩形框与硬墙。在粒子作扩散运动的情况下，我们发现跳跃时间在阈值区以指数-（3/2）的幂律发散。在粒子惯性运动的条件下，过渡态理论预测了指数为-2的幂律行为。分子动力学模拟证实了惯性动力学的过渡态理论结果，而布朗动力学模拟表明标度指数对算法的细节高度敏感。
The dynamical transition between the anomalous single file diffusion of highly confined fluids and bulk normal diffusion can be described by a phenomenological model involving a particle hopping time tau(hop). We suggest a theoretical formalism that will be useful for the calculation of tau(hop) for a variety of systems and test it using a simple model consisting of two hard disks confined to a rectangular box with hard walls. In the case where the particles are moving diffusively, we find the hopping time diverges as a power law in the threshold region with an exponent of -(3/2). Under conditions where the particles move inertially, transition state theory predicts a power law behavior with an exponent of -2. Molecular dynamics simulations confirm the transition state theory result for inertial dynamics, while Brownian dynamics simulations suggest the scaling exponent is highly sensitive to the details of the algorithm.