PSL Research University, Chimie Paristech-CNRS , Institut de Recherche de Chimie de Paris , 11 rue P. et M. Curie , 75005 Paris , France.
Dipartimento di Chimica IFM , Università di Torino and NIS - Nanostructured Interfaces and Surfaces - Centre of Excellence , Via P. Giuria 7 , 10125 Torino , Italy.
J Chem Theory Comput. 2018 Nov 13;14(11):5969-5983. doi: 10.1021/acs.jctc.8b00762. Epub 2018 Nov 1.
We present the implementation of an implicit solvation model in the CRYSTAL code. The solvation energy is separated into two components: the electrostatic contribution arising from a self-consistent reaction field treatment obtained within a generalized finite-difference Poisson model, augmented by a nonelectrostatic contribution proportional to the solvent-accessible surface area of the solute. A discontinuous dielectric boundary is used, along with a solvent-excluded surface built from interlocking atom-centered spheres on which apparent surface point charges are mapped. The procedure is general and can be performed at both the Hartree-Fock and density functional theory levels, with pure or hybrid functionals, for systems periodic in 0, 1, and 2 directions, that is, for isolated molecules and extended polymers and surfaces. The Poisson equation resolution and apparent surface charge formalism is first validated on model analytical test cases. The good agreement obtained on solvation free energies is further confirmed by calculations performed on a large test set of 501 neutral molecules, for which a mean unsigned error of 1.3 kcal/mol is obtained when compared to the available experimental data. Importantly, the self-consistent reaction field procedure converges well for all molecules tested. This is further verified for all polymers and surfaces considered. In particular, for periodic systems, results obtained on an infinite glycine chain and on the wettability parameters of SiO surfaces are in good agreement with previously published data. The size extensivity of the energetic terms involved in the electrostatic contribution to the solvation energy is also well verified. These encouraging results constitute a first step to take into account complex environments in the CRYSTAL code, potentially allowing for a more accurate modeling of complex processes for both periodic and nonperiodic systems.
我们在 CRYSTAL 代码中实现了一种隐式溶剂化模型。溶剂化能分为两个部分：静电贡献来自于广义有限差分泊松模型中获得的自洽反应场处理，加上与溶剂可及表面积成正比的非静电贡献。使用不连续介电边界和由互锁原子中心球构建的溶剂排除表面，在其上映射表观表面点电荷。该过程是通用的，可以在 Hartree-Fock 和密度泛函理论水平上进行，使用纯或混合泛函，针对在 0、1 和 2 方向上周期性的系统，即孤立分子和扩展聚合物和表面。泊松方程求解和表观表面电荷形式首先在模型分析测试案例上进行验证。在 501 个中性分子的大型测试集中进行计算时，获得的溶剂化自由能的良好一致性进一步得到了确认，与可用的实验数据相比，平均未签名误差为 1.3 kcal/mol。重要的是，对于所有测试的分子，自洽反应场过程都很好地收敛。这对于所有考虑的聚合物和表面都得到了验证。特别是对于周期性系统，在无限甘氨酸链和 SiO 表面润湿性参数上获得的结果与先前发表的数据一致。溶剂化能静电贡献所涉及的能量项的大小扩展性也得到了很好的验证。这些令人鼓舞的结果构成了在 CRYSTAL 代码中考虑复杂环境的第一步，可能允许对周期性和非周期性系统的复杂过程进行更准确的建模。
