SiO_2体系的分子动力学研究

Study on molecular reaction dynamics for SiO_2 system

基于多体项展式理论方法导出的SiO_2分子基态(X^1A_1)的分析势能函数,用准经典的Monte-Carlo轨线法对Si(~3P_g)+OO'(X^3∑_g^-)和O(~1D_g)+SiO'(X^1∑^+)体系的分子反应动力学过程进行了计算.结果表明Si(~3P_g)+OO'(X^3∑_g^-)体系生成络合物是一个阈能比较小的反应,而生成离解产物则是一个有比较大的阈能反应,其阈能值约为200 kJ·mol^(-1),说明主要以生成络合物为主;O(~1D_g)+SiO'(X^1∑^+)体系没有络合物生成,生成离解产物O(~1D_g)+SiO'(X^1∑^+)→O+O'+Si的反应截面比非反应碰撞产物O(~1D_g)+SiO'(X^1∑^+)→Si+OO'的反应截面要大约两个数量级,在低能区是有阈能的反应,其阈能值约为120 kJ·mol^(-1).

Molecular reaction dynamics for the collision Si（^3P8）＋OO’（X^3∑g） and O（^1Dg）＋SiO＇（X^1∑^＋） have been studied based on the analytical potential energy function of SiO2 （X^1A1） by Monte- Carlo quasi-classical trajectory approach. The results of the collision process indicate that there is less threshold energy for complex compound reaction than dissociation in Si（^3P8）＋OO’（X^3∑g） system, but the dissociation compound reaction with about 200 kJ·Mol^-1 threshold energy. There is not complex compound, and the reactive cross section for dissociation reaction far great than not reaction in O（^1Dg）＋SiO＇（X^1∑^＋） system. It is shown that the complex compound give priority to than others in Si（^3P8）＋OO＇（X^3∑g） system and the dissociation production reaction predominates in O（^1Dg）＋SiO＇（X^1∑^＋） system with threshold energy with about 120 kJ ·mol^-1 in low-lying energy section.