Intramolecular Conversions Over Low Barriers IX: Vibrational Bottle-Necks at Statistical Equilibrium
Intramolecular Conversions Over Low Barriers IX: Vibrational Bottle-Necks at Statistical Equilibrium
复制标题
低势垒下的分子内转化 IX：统计平衡处的振动瓶颈
DOI：
10.1002/bbpc.198800083
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
N. Chiu
中科院分区：
文献类型：
--
作者：
S. Bauer;D. Borchardt;N. Chiu
IVR 速率瓶颈的存在由一组双分子速率常数在低密度下对密度的反相关性表明。先前提出的动态平衡系统（典型的低势垒异构化）弛豫时间模型可以扩展，以使各个振动状态的作用变得透明。可以明确地引入耦合参数（对于每个分子种类），该参数将分子内能量转移的概率与必须从非相关振荡器转换为包含反应坐标（ζ）的能量（υα）的能量量相关联。基本函数是 f(q; E)，它是区间 E 和 (E + ΔE) [对于总状态密度 g(E)] 内的状态数，其中包含任何特定 v 状态的激发。总能量空间被划分为大量“带”，在这些“带”之间发生碰撞和无碰撞能量转移。弛豫时间是从大长期行列式的最低非零根获得的。
The presence of bottle-necks in IVR rates is indicated by the inverse dependence of a group of bimolecular rate constants on density, at low densities. The previously proposed model for relaxation times of systems in dynamic equilibrium (typical of isomerizations over low barriers) can be extended to make transparent the role of individual vibrational states. A coupling parameter can be explicitly introduced (for each molecular species) which relates the probability for intramolecular energy transfers to the amounts of energy which have to be converted from the non-involved oscillators to the one (υα) which comprises the reaction coordinate (ζ). The essential function is f(q; E), which is the number of states within the interval E and (E + ΔE) [for a total state density g(E)] which incorporate excitation of any particular v, state. The total energy space is divided into a large number of “bands” between which both collisional and collisionless energy transfers take place. The relaxation time is obtained from the lowest non-zero root of a large secular determinant.