GENERAL METHOD FOR NUMERICALLY SIMULATING STOCHASTIC TIME EVOLUTION OF COUPLED CHEMICAL-REACTIONS
GENERAL METHOD FOR NUMERICALLY SIMULATING STOCHASTIC TIME EVOLUTION OF COUPLED CHEMICAL-REACTIONS
复制标题
DOI：
10.1016/0021-9991(76)90041-3
复制
发表时间：
1976-01-01
影响因子：
4.1
通讯作者：
GILLESPIE, DT
中科院分区：
文献类型：
--
作者：
GILLESPIE, DT
在化学动力学随机公式的框架内，提出了一种精确的方法，用于数值计算通过一组特定的耦合化学反应通道相互作用的任何空间均匀的分子物种混合物的时间演化。该方法是一个紧凑的、面向计算机的蒙特卡罗仿真程序。它对于模拟混合良好的气相系统的瞬态行为特别有用，其中许多分子种类参与许多高度耦合的化学反应。对于波动和相关性没有显著作用的“普通”化学系统，该方法可以替代传统的数值求解确定性反应速率方程的方法。对于接近化学不稳定性的非线性系统，其中波动和相关性可能使确定性方程失效，该方法是数值检验随机主方程预测的有效方法。虽然与空间齐次主方程完全等价，但这里提出的数值模拟算法更直接地基于一个新定义的实体，称为“反应概率密度函数”。本文的目的是描述模拟算法的机制，并以严格的、先验的方式建立其物理和数学有效性；具体化学系统的数值应用将在以后的出版物中介绍。
An exact method is presented for numerically calculating, within the framework of the stochastic formulation of chemical kinetics, the time evolution of any spatially homogeneous mixture of molecular species which interreact through a specified set of coupled chemical reaction channels. The method is a compact, computer-oriented, Monte Carlo simulation procedure. It should be particularly useful for modeling the transient behavior of well-mixed gas-phase systems in which many molecular species participate in many highly coupled chemical reactions. For “ordinary” chemical systems in which fluctuations and correlations play no significant role, the method stands as an alternative to the traditional procedure of numerically solving the deterministic reaction rate equations. For nonlinear systems near chemical instabilities, where fluctuations and correlations may invalidate the deterministic equations, the method constitutes an efficient way of numerically examining the predictions of the stochastic master equation. Although fully equivalent to the spatially homogeneous master equation, the numerical simulation algorithm presented here is more directly based on a newly defined entity called “the reaction probability density function.” The purpose of this article is to describe the mechanics of the simulation algorithm, and to establish in a rigorous, a priori manner its physical and mathematical validity; numerical applications to specific chemical systems will be presented in subsequent publications.