【摘要】 采用球型模型和点位－点位模型对超临界二氧化碳的自扩散系数及苯或萘在超临界二氧化碳中的无限稀释扩散系数进行了分子动力学模拟．结果表明，球型模型及点位－点位模型均可较准确地预测二氧化碳的自扩散系数，球型模型因形式简单，准确度相对较差；点位－点位模型准确度虽高，但需较长的模拟机时．两种位能模型所获得的准确度相当，但点位－点位模型可以更精细地反映体系的微观结构．更多还原

【Abstract】 The self-diffusion coefficients of supercritical carbon dioxide and the infinite dilute diffusion coefficients of benzene and naphthalene in supercritical carbon dioxide were investigated by MD simulation with spherical Lennard-Jones model and site-site model respectively. It was shown that both spherical model and site-site model could be used to predict the self-diffusion coefficients of supercritical carbon dioxide well. The site-site model could be used to predict the self-diffusion coefficients more precisely than the spherical model does. An attempt has been made to compare the simulation results of infinite dilute diffusion coefficients of benzene and naphthalene in supercritical carbon dioxide between simple spherical model and site-site model. It was found that there was scarcely any difference between the prediction accuracies obtained from the two models. The site-site model could probe the detailed microstructure of supercritical systems more precisely.更多还原