Absolute classical densities of states for very anharmonic systems and applications to the evaporation of rare gas clusters
Absolute classical densities of states for very anharmonic systems and applications to the evaporation of rare gas clusters
复制标题
非常非调和系统的绝对经典态密度及其在稀有气体团簇蒸发中的应用
DOI：
10.1063/1.464952
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
F. Amar
中科院分区：
文献类型：
--
作者：
S. Weerasinghe;F. Amar
我们用分子动力学方法模拟了团簇离解反应Arn→Arn−1+Ar（12≤n≤14），给出了明确定义的内能和总角动量。反应速率和动能释放分布进行比较，预测的几个统计理论：赖斯，Ramsperger，和卡塞尔（RRK），恩格尔金，和相空间理论（PST）。我们采用鼻子处方恒温动力学加上多直方图的方法Labastie和惠顿获得高度准确的振动态密度的集群。绝对密度由Reinhardt的绝热转换方法确定。将这些精确的非谐振动态密度纳入经典PST，使我们能够直接与模拟结果进行比较，并消除了理论中的任何参数。然后PST预测的蒸发动力学给出了低能量（长时间尺度）制度，MD模拟是昂贵的。
We have simulated the cluster dissociation reaction Arn→Arn−1+Ar (12≤n≤14) using molecular dynamics (MD) with well defined internal energy and total angular momentum. Reaction rates and kinetic energy release distributions are compared to the predictions of several statistical theories: Rice, Ramsperger, and Kassel (RRK), Engelking, and phase space theory (PST). We employ the Nose prescription for constant temperature dynamics coupled with the multiple histogram method of Labastie and Whetten to obtain highly accurate vibrational densities of states for the clusters. The absolute densities are determined by the adiabatic switching method of Reinhardt. Incorporation of these accurate anharmonic vibrational densities of states into classical PST allows us to make a direct comparison with the simulation results and eliminates any parameters from the theory. Then PST predictions for the kinetics of evaporation are given for the low energy (long time scale) regime where MD simulations are prohibitively expensi...