Photochemistry Center and Institute of Applied Mechanics, Russian Academy of Sciences, Moscow, Russia.
J Phys Chem B. 2010 Feb 25;114(7):2457-66. doi: 10.1021/jp9064399.
The modification of the electrostatic continuum solvent model considered in the present work is based on the exact solution of the Poisson equation, which can be constructed provided that the dielectric permittivity epsilon of the total solute and solvent system is an isotropic and continuous spatial function. This assumption allows one to formulate a numerically efficient and universal computational scheme that covers the important case of a variable epsilon function inherent to the solvent region. The obtained type of solution is unavailable for conventional dielectric continuum models such as the Onsager and Kirkwood models for spherical cavities and the polarizable continuum model (PCM) for solute cavities of general shape, which imply that epsilon is discontinuous on the boundary confining the excluded volume cavity of the solute particle. Test computations based on the present algorithm are performed for water and several nonaqueous solvents. They illustrate specific features of this approach, called the "smooth boundary continuum model" (SBCM), as compared to the PCM procedure, and suggest primary tentative results of its parametrization for different solvents. The calculation for the case of a binary solvent mixture with variable epsilon in the solvent space region demonstrates the applicability of this approach to a novel application field covered by the SBCM.
本工作中所考虑的静电连续体溶剂模型的修正基于泊松方程的精确解，只要总溶质和溶剂体系的介电常数 ε 是各向同性和连续的空间函数，就可以构建该解。这一假设允许人们制定一种数值高效且通用的计算方案，涵盖了溶剂区域固有可变 ε 函数的重要情况。对于传统的介电连续体模型，如球形腔的 Onsager 和 Kirkwood 模型以及一般形状溶质腔的极化连续体模型 (PCM)，无法获得这种类型的解，因为它们意味着 ε 在限制溶质粒子排斥体积腔的边界上是不连续的。基于本算法进行的测试计算针对水和几种非水溶剂。它们说明了与 PCM 程序相比，这种称为“光滑边界连续体模型”(SBCM)的方法的具体特点，并提出了针对不同溶剂的初步参数化结果。在溶剂空间区域具有可变 ε 的二元溶剂混合物的情况下进行的计算表明，该方法适用于 SBCM 涵盖的新应用领域。
