醇及脱氧核糖与水分子间三体作用强度的快速准确计算

Rapid and Accurate Calculation of the Three⁃body Interaction Strength in the Hydrogen⁃bonded Complexes of Alcohols or Deoxyribose with Water

快速准确预测醇及脱氧核糖分子与水形成的氢键复合物的三体作用强度,对准确模拟水环境下蛋白质和DNA的结构和功能至关重要.基于对多体极化作用的理解,在可极化偶极-偶极作用模型(PBFF)基础上,将体系中的极性化学键视为化学键偶极,通过模拟键偶极的极化计算了醇及脱氧核糖与水分子形成的氢键复合物的三体作用能.通过拟合甲醇与水氢键复合物的三体作用能随分子间距离变化的能量曲线确定了所需的参数.将模型和所确定的参数应用于计算更多的甲醇、乙醇及脱氧核糖与水氢键复合物的三体作用能,检验了模型的准确性和参数的可转移性.计算结果表明,可极化偶极-偶极作用模型及所确定的参数能够较好地预测具有不同结构的氢键复合物的三体作用强度,其精度可与MP2方法的计算精度相当.

It is important to accurately and rapidly calculate the three-body interaction energies in the hydrogen-bonded complexes of alcohols or deoxyribose with water,especially for simulating the structures and functions of proteins and DNA in aqueous environments.Based on the understanding of the essence of many-body polarization effects,we estimated the three-body interaction energies of the hydrogen-bonded complexes composed of alcohols or deoxyribose with water via the polarizable dipole-dipole interaction model through regarding the polar chemical bonds O-H and C-O as bond-dipoles.The corresponding parameters were obtained by fitting to the three-body interaction energy curves with respect to the intermolecular distance of a methanol-water complex.The accuracy of our model and the transferability of parameters were validated through calculating the three-body interaction energies of the complexes of methanol,ethanol or deoxyribose with water.The calculated results demonstrated that our polarizable dipole-dipole interaction model and the parameters determined in this work can accurately estimate the three-body interaction energies of different hydrogen-bonded complexes,and the accuracy of our model is comparable with that of MP2 method.