Marenich Aleksandr V, Cramer Christopher J, Truhlar Donald G
Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota 55455-0431.
J Chem Theory Comput. 2009 Sep 8;5(9):2447-64. doi: 10.1021/ct900312z. Epub 2009 Aug 12.
We present a new self-consistent reaction field continuum solvation model based on the generalized Born (GB) approximation for the bulk electrostatic contribution to the free energy of solvation. The new model improves on the earlier SM8 model by using the asymmetric descreening algorithm of Grycuk to treat dielectric descreening effects rather than the Coulomb field approximation; it will be called Solvation Model 8 with asymmetric descreening (SM8AD). The SM8AD model is applicable to any charged or uncharged solute in any solvent or liquid medium for which a few key descriptors are known, in particular dielectric constant, refractive index, bulk surface tension, and acidity and basicity parameters. It does not require the user to assign molecular mechanics types to an atom or a group; all parameters are unique and continuous functions of geometry. This model employs a single set of parameters (solvent acidity-dependent intrinsic Coulomb radii for the treatment of bulk electrostatics and solvent description-dependent atomic surface tensions coefficients for the treatment of nonelectrostatic and short-range electrostatic effects). The SM8AD model was optimized over 26 combinations of theoretical levels including various basis sets (MIDI!, 6-31G*, 6-31+G*, 6-31+G**, 6-31G**, cc-pVDZ, DZVP, 6-31B*) and electronic structure methods (M05-2X, M05, M06-2X, M06, M06-HF, M06-L, mPW1PW, mPWPW, B3LYP, HF). It may be used with confidence with any level of electronic structure theory as long as self-consistently polarized Charge Model 4 or other self-consistently polarized charges compatible with CM4 charges are used, for example, CM4M charges can be used. With M05-2X/6-31G*, the SM8AD model achieves a mean unsigned error of 0.6 kcal/mol on average over 2 560 solvation free energies of tested aqueous and nonaqueous neutral solutes and a mean unsigned error of 3.9 kcal/mol on average over 332 solvation free energies of aqueous and nonaqueous ions.
我们提出了一种基于广义玻恩（GB）近似的新的自洽反应场连续介质溶剂化模型，用于计算溶剂化自由能中的体静电贡献。新模型在早期的SM8模型基础上进行了改进，采用了Grycuk的非对称去屏蔽算法来处理介电去屏蔽效应，而不是库仑场近似；它将被称为具有非对称去屏蔽的溶剂化模型8（SM8AD）。SM8AD模型适用于任何溶剂或液体介质中的任何带电或不带电溶质，只要知道几个关键描述符，特别是介电常数、折射率、体表面张力以及酸度和碱度参数。它不要求用户为原子或基团指定分子力学类型；所有参数都是几何结构的唯一连续函数。该模型采用一组参数（用于处理体静电的与溶剂酸度相关的固有库仑半径，以及用于处理非静电和短程静电效应的与溶剂描述相关的原子表面张力系数）。SM8AD模型在包括各种基组（MIDI!、6 - 31G*、6 - 31+G*、6 - 31+G**、6 - 31G**、cc - pVDZ、DZVP、6 - 31B*）和电子结构方法（M05 - 2X、M05、M06 - 2X、M06、M06 - HF、M06 - L、mPW1PW、mPWPW、B3LYP、HF）的26种理论水平组合上进行了优化。只要使用自洽极化电荷模型4或其他与CM4电荷兼容的自洽极化电荷，例如可以使用CM4M电荷，它就可以与任何水平的电子结构理论放心使用。使用M05 - 2X/6 - 31G*时，SM8AD模型在2560个测试的水性和非水性中性溶质的溶剂化自由能上平均实现了0.6 kcal/mol的平均绝对误差，在332个水性和非水性离子的溶剂化自由能上平均实现了3.9 kcal/mol的平均绝对误差。
