应用分子模拟求取流体化学势的新途径

A NEW METHOD FOR THE ESTIMATION OF CHEMICAL POTENTIAL IN MOLECULAR SIMULATION

提出了分子模拟中求取流体化学势的新途径——参考试验粒子方法、通过适当选择参考试验粒子,避免了试验粒子的插入操作和计算,同时解决了移出粒子方法在Metropolis取样构型中难以得到正确结果的缺陷.应用该方法对ρσ~3=0.5和 0.65的硬球流体以及kT/ε=1.2时ρσ~3=0.65、0.70、0.80、0.90的Lennard-Jones流体的研究结果表明,该方法具有收敛快、计算量小和精度高的优点.

A new method for the estimation of chemical potential in molecular simulation, the Reference Test Particle method, is proposed. This method is more efficient than the particle-insertion method and overcomes the drawback of underestimate obtained with the particle-removal method. Application of the new method to hard sphere fluids at ρσ3 = 0.50 and o.65 and Lennard-Jones fluids at ρσ3 = 0.65, 0.70, 0.80 and o.90 along the isotherm kT/ ε= 1.2 shows that the RTP method has the advantages of fast convergence, high efficiency and good accuracy.