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  

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

作　　者：杜奇石[1] 魏冬青[1] 

机构地区：[1]天津师范大学生物信息与药物开发研究所,天津300074

出　　处：《化学学报》2004年第2期120-126,共7页Acta Chimica Sinica

基　　金：天津市科委基础科学重点项目 (No.0 2 361 82 1 1 )资助

摘　　要：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 。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 〈Δ μ (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.

关 键 词：桥函数 统计力学 积分方程理论 溶剂化自由能 计算精度 改进 超链模型 

分 类 号：O645[理学—物理化学]