化学学报 ›› 2004, Vol. 62 ›› Issue (2): 120-126. 上一篇    下一篇

研究论文

桥函数在统计力学积分方程理论3d-RISM-HNC的应用和溶剂化自由能计算的改进

杜奇石, 魏冬青   

  1. 天津师范大学, 生物信息与药物开发研究所, 天津, 300074
  • 投稿日期:2003-04-08 修回日期:2003-07-24 发布日期:2014-01-26
  • 通讯作者: 杜奇石,E-mail:du70_45@hotmail.com;Fax:022-23540187. E-mail:du70_45@hotmail.com
  • 基金资助:
    天津市科委基础科学重点项目(No.023618211)资助.

Application of Bridge Functions in Statistical Mechanical Integral Equation Theory 3d-RISM-HNC and Improvement in the Calculation of Solvation Free Energy

DU Qi-Shi, WEI Dong-Qing   

  1. Institute of Bioinformatics and Drug Discovery, Tianjin Normal University, Tianjin 300074
  • Received:2003-04-08 Revised:2003-07-24 Published:2014-01-26

把氢-桥函数和氧-桥函数应用于统计力学积分方程理论的三维的参考作用点-超链模型(3d-RISM-HNC)中,用以改进极性和非极性溶质的水溶液的热力学性质的计算.用三维和二维图形考察了溶剂水分子的氢原子和氧原子的桥函数在改进溶剂作用点的平均密度分布函数〈ρH(r)〉和〈ρO(r)〉,和平均超额化学势〈Δμ(r)〉的计算的效果.计算结果表明,氢桥函数和氧桥函数极大地改进了3d-RISM-HNC 方法的精度,把这一方法提高到定量和半定量的水平.研究表明,溶质分子的作用点的超额化学势的径向分布函数〈Δμ(r)〉比平均密度分布函数〈ρs(r)〉能够更灵敏地反映桥函数的改进效果.研究表明,为提高3d-RISM-HNC 方法的精度,需要进一步改进桥函数的函数形式和优化其中的参数.

关键词: 统计力学, 积分方程理论, 溶剂化自由能, 溶液理论

The hydrogen and oxygen bridge functions were applied in 3d-RISM-HNC based on the integral equation theory of statistical mechanics, which was used to improve the calculations of thermodynamic properties of polar and non polar solutions. The effects of bridge functions on solvent sites and average excess chemical potentials 〈Δμ(r)〉 are checked using radial and three-dimensional figures. Promising improvements in average excess chemical potentials and solvent particle density distributions were observed with the complement of hydrogen and oxygen bridge functions. However, there is still a distance in the quantitative calculations of thermodynamic properties of polar solutions. More accurate bridge functions are needed for further improvement in accuracy of 3d-RISM-HNC.

Key words: statistical mechanics, integral equation theory, solvation free energy, solution theory