线型分子势能函数及第二维里系数计算

Potential Energy Function and the Second Virial Coefficients of the Linear Molecules

本文以两中心的Lennard-Jones(2CLJ)流体为研究对象,通过引入与温度相关的势能参数,提出了改进型的2CLJDQP势能函数模型。应用此模型计算了乙烷(C_2H_6)、六氟乙烷(C_2F_6)、氟甲烷(CH3F)、氯甲烷(CH_3Cl)、1,1,1-三氟乙烷(CH3CF3)、二氟乙烷(CH_3CHF_2)的第二维里系数,较之2CLJDQP模型的计算结果,引进温度修正的改进型2CLJDQP势能函数模型计算精度显著提高,更加真实地描述了线型分子间的相互作用。计算结果表明,其中,以上物质第二维里系数的计算偏差分别为2.87%、5.45%、1.74%、5.85%、2.29%、2.31%。

By introducing the potential parameters associated with temperature, the improved 2CLJDQP potential model has been presented. The second virial coefficients of C2H6, C2F6, CH3F, CH3C1, CH3CF3 and CH3CHF2 have been calculated from the improved 2CLJDQP model. The results show that the accuracy of second virial coefficient has been improved significantly using the new model, which describe the interaction between linear molecules more realistically. And the calculation deviations of the second virial coefficient of above substances are 2.87%, 5.45%, 1.74%, 5.85%, 2.29%, 2.31% respectively.