Prediction of tautomer ratios by embedded-cluster integral equation theory
Prediction of tautomer ratios by embedded-cluster integral equation theory
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DOI：
10.1007/s10822-010-9340-x
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发表时间：
2010-04-01
影响因子：
3.5
通讯作者：
Schmidt, K. Friedemann
中科院分区：
文献类型：
--
作者：
Kast, Stefan M.;Heil, Jochen;Schmidt, K. Friedemann
嵌入式簇参考相互作用位点模型（EC-RISM）方法结合了热力学-力学积分方程理论和量子化学计算，用于预测溶液中化学反应的热力学数据。溶质的电子结构与溶剂的结构自洽地确定，所述溶剂的结构由3D RISM积分方程理论描述。连续的溶剂位分布被映射到一组离散的背景电荷（“嵌入式集群”），代表一个额外的贡献的分子哈密顿。互变异构体的SAMPL 2挑战集的EC-RISM分析分三个阶段进行。首先，一组化合物的定量实验自由能数据提供的几何优化和自由能预测确定适当的量子化学理论水平。其次，将产生的工作流程应用于全套，以便对结果进行化学解释。第三，部分化合物的实验数据的披露有助于详细分析方法问题和建议，为未来的改进模型。在没有特别调整参数的情况下，EC-RISM模型在SAMPL 2参与者中产生第一组（0.6 kcal mol（-1））以及完整的定量反应数据组（2.0 kcal mol（-1））的均方根误差的最小值。
The "embedded cluster reference interaction site model" (EC-RISM) approach combines statistical-mechanical integral equation theory and quantum-chemical calculations for predicting thermodynamic data for chemical reactions in solution. The electronic structure of the solute is determined self-consistently with the structure of the solvent that is described by 3D RISM integral equation theory. The continuous solvent-site distribution is mapped onto a set of discrete background charges ("embedded cluster") that represent an additional contribution to the molecular Hamiltonian. The EC-RISM analysis of the SAMPL2 challenge set of tautomers proceeds in three stages. Firstly, the group of compounds for which quantitative experimental free energy data was provided was taken to determine appropriate levels of quantum-chemical theory for geometry optimization and free energy prediction. Secondly, the resulting workflow was applied to the full set, allowing for chemical interpretations of the results. Thirdly, disclosure of experimental data for parts of the compounds facilitated a detailed analysis of methodical issues and suggestions for future improvements of the model. Without specifically adjusting parameters, the EC-RISM model yields the smallest value of the root mean square error for the first set (0.6 kcal mol(-1)) as well as for the full set of quantitative reaction data (2.0 kcal mol(-1)) among the SAMPL2 participants.