Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
Department of Chemistry, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
J Chem Theory Comput. 2023 Mar 14;19(5):1446-1456. doi: 10.1021/acs.jctc.2c00805. Epub 2023 Feb 13.
We present a novel multiscale approach to study the electronic structure of open shell molecular systems embedded in an external environment. The method is based on the coupling of multilevel Hartree-Fock (MLHF) and Density Functional Theory (MLDFT), suitably extended to the unrestricted formalism, to Molecular Mechanics (MM) force fields (FF). Within the ML region, the system is divided into active and inactive parts, thus describing the most relevant interactions (electrostatic, polarization, and Pauli repulsion) at the quantum level. The surrounding MM part, which is formulated in terms of nonpolarizable or polarizable FFs, permits a physically consistent treatment of long-range electrostatics and polarization effects. The approach is extended to the calculation of hyperfine coupling constants and applied to selected nitroxyl radicals in an aqueous solution.
我们提出了一种新的多尺度方法来研究嵌入在外部环境中的开壳分子系统的电子结构。该方法基于多水平 Hartree-Fock（MLHF）和密度泛函理论（MLDFT）的耦合，适当扩展到非限制形式，以与分子力学（MM）力场（FF）相结合。在 ML 区域内，系统被分为活动部分和非活动部分，从而在量子水平上描述最相关的相互作用（静电、极化和 Pauli 排斥）。周围的 MM 部分是根据不可极化或可极化 FF 来构建的，这允许对长程静电和极化效应进行物理上一致的处理。该方法扩展到超精细耦合常数的计算，并应用于水溶液中的选定氮氧自由基。
