Free Energy of Homogeneous Nucleation in the Supersaturated Vapor Phase

通过对饱和Lennard-Jones汽相的MonteCarlo模拟，估算了均匀形核的自由能。该计算是在具有固定粒子数N的每个系统上执行的。假设了周期性边界条件。每个粒子的体积为43.2，单位为Lennard-Jones系统。不包括载气颗粒。温度范围为0.01至1.00，单位为Lennard-Jones系统。初始构型为畸变立方晶格，样品冷却至低温，所有分子变成大的团簇。在第二阶段中，将其加热以蒸发，其中获得单体相。在第三次运行中，低温样品被加热的条件下，不允许簇在蒙特卡罗模拟中分解。通过热力学积分得到了团簇相和单体相的自由能。得到的临界尺寸与载气粒子的分子动力学模拟是相容的。

The free energy of homogeneous nucleation is estimated by the Monte Carlo simulations on the saturated Lennard-Jones vapor phase. The calculation is performed on the each system with a fixed number of particles N. The periodic boundary condition is assumed. The volume per a particle is 43.2 in units of Lennard-Jones system. No carrier gas particles are included. The range of temperature is form 0.01 up to 1.00 in units of Lennard-Jones system. The initial configuration is distorted cubic lattice, and the sample is cooled to low temperature, where all molecules become a large cluster. In the second stage, it is heated to vaporize, where the monomer phase is obtained. In the third run, the low temperature samples is heated with a condition that the cluster is not allowed to decompose in the Monte Carlo simulations. The free energies of the cluster phase and the monomer one is obtained by the thermodynamic integration. The obtained critical size is compatible to the molecular dynamics simulation with the carrier gas particles.