Method for predicting IVR-limited unimolecular reaction rate coefficients
Method for predicting IVR-limited unimolecular reaction rate coefficients
复制标题
IVR限制单分子反应速率系数的预测方法
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
D. Thompson
中科院分区：
文献类型：
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作者：
D. Shalashilin;D. Thompson
我们提出了一种基于扩散理论的方法（即，经典的主方程），用于计算高能量下的单分子反应速率，其中反应受到IVR（分子内振动能量再分布）速率的限制。该方法，我们称之为分子内动力学扩散理论（IDDT），使用短时间（几个fs）的经典轨迹的结果，以确定初始微正则分布的演变的特征时间，或者，更具体地说，IVR之间的反应坐标和“浴”模式的分子的速率。IDDT方法准确地预测在非统计，IVR控制的制度，证明了一个标准的经典轨迹模拟的结果相比，在Si 2 H6的Si-Si键裂变率。该方法需要的计算机时间比标准的经典弹道计算少得多。该方法可用于获得从动力学状态到统计状态（阈值附近）的结果，其中…
We present a method based on diffusion theory (i.e., a classical master equation) for calculating unimolecular reaction rates at high energies where reaction is limited by the IVR (intramolecular vibrational energy redistribution) rate. The method, which we refer to as intramolecular dynamics diffusion theory (IDDT), uses short-time (a few fs) classical trajectory results to determine the characteristic times for the evolution of an initial microcanonical distribution, or, more specifically, the rate of IVR between the reaction coordinate and the “bath” modes of the molecule. The IDDT method accurately predicts the rate of Si–Si bond fission in Si2H6 in the nonstatistical, IVR-controlled regime, as demonstrated by comparisons with the results of a standard classical trajectory simulation. The method requires much less computer time than do the standard classical trajectory calculations. The method can be used to obtain results from the dynamical regime down to the statistical regime (near threshold), wher...