Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, Ohio 44115, USA.
J Chem Phys. 2019 Feb 21;150(7):074303. doi: 10.1063/1.5080314.
Clusters are treated in the microcanonical ensemble. Two classical choices for the partition function are used in Boltzmann's assumption for entropy: Phase space volume and phase space density. For both definitions, exact statistical analogs are derived for energy derivatives of entropy to arbitrary order. The analogs are used in rigorous microcanonical Monte Carlo simulation to measure entropy derivatives up to order three for systems of three and four atoms. All simulation results are confirmed by direct numerical integration of the statistical analogs.
簇在正则系综中处理。在玻尔兹曼的熵假设中，有两种经典的划分函数选择：相空间体积和相空间密度。对于这两种定义，都推导出了精确的统计模拟，用于任意阶的熵的能量导数。这些模拟用于严格的正则蒙特卡罗模拟中，以测量三个和四个原子系统中熵导数的三阶。所有的模拟结果都通过统计模拟的直接数值积分来验证。
