A_2B模型分子经典轨迹的辛算法计算

Computing Classical Trajectories of Model Molecule A2B by Symplectic Algorithm

采用辛算法计算了Ａ２Ｂ模型分子的经典轨迹并与传统Ｒｕｎｇｅ－Ｋｕｔｔａ （Ｒ－Ｋ）算法进行了比较．结果表明，在微观反应动力学研究所应考虑的时间范围内，辛算法的结果与理论分析一致，Ｒ－Ｋ法的结果则面目全非．因此，用辛算法替代传统数值方法有可能克服目前经典轨迹计算存在的困难，从根本上改进微观反应动力学研究的经典轨迹方法．

Classical trajectories of model molecule A2B are calculated by means of both Symplectic and Runge-Kutta algorithms. The comparisons beween the results of the two are illustrated by figures. Further analyses indicate : Within the whole domain of time that should be considered by micro chemical reaction dynamics, the trajectories calculated from symplectic algorithm are always identical with physical analysis, but those from Runge-Kut-ta's are irregular and unpredicatable. Moreover, computation of classical trajectory by symplectic algorithm instead of traditional numerical approaches may critically improve classical trajectory method in chemical reaction dynamics.