Napari Ismo, Vehkamaki Hanna
Department of Physical Sciences, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki, Finland.
J Chem Phys. 2004 Jul 8;121(2):819-22. doi: 10.1063/1.1763148.
Evaporation of small Lennard-Jones argon clusters has been studied using molecular dynamic simulations. An extensive library of clusters with 4, 5, 6, 11, and 21 atoms has been obtained from an earlier study. Analysis of the evaporation properties of the clusters indicate, that the fraction of dimer evaporations of all evaporation events increases with the total energy of the cluster. The fraction of evaporated dimers from clusters with a constant lifetime is independent of the cluster size for short-lived clusters and increases with cluster size for long-lived clusters. Only a few percent of the clusters which are long lived enough to participate in vapor-liquid nucleation decay by emitting dimers. The mean cluster lifetime as a function of total energy shows the same exponentially decreasing trend for monomer and dimer evaporation channels. The fraction of trimer evaporations is found to be vanishingly small.
利用分子动力学模拟研究了小尺寸的 Lennard-Jones 氩团簇的蒸发过程。通过早期研究已获得了包含 4、5、6、11 和 21 个原子的大量团簇库。对团簇蒸发特性的分析表明，在所有蒸发事件中，二聚体蒸发的比例随团簇总能量的增加而增加。对于寿命恒定的团簇，短寿命团簇中蒸发二聚体的比例与团簇大小无关，而长寿命团簇中该比例随团簇大小增加。只有极少数寿命足够长、能够参与气液成核的团簇通过发射二聚体而衰变。单体和二聚体蒸发通道的平均团簇寿命作为总能量的函数呈现出相同的指数下降趋势。发现三聚体蒸发的比例极小。
