ONIOM Method with Charge Transfer Corrections (ONIOM-CT): Analytic Gradients and Benchmarking
ONIOM Method with Charge Transfer Corrections (ONIOM-CT): Analytic Gradients and Benchmarking
复制标题
带有电荷转移校正的 ONIOM 方法 (ONIOM-CT)：解析梯度和基准测试
DOI：
10.1021/acs.jctc.2c00584
复制
发表时间：
2022
影响因子：
5.5
通讯作者：
Raghavachari, Krishnan
中科院分区：
文献类型：
--
作者：
Tripathy, Vikrant;Mayhall, Nicholas J.;Raghavachari, Krishnan
使用不同方法处理大分子的不同区域的混合方法，如ONIOM，被广泛用于研究各种材料和生物系统中的化学反应。然而，由于使用氢连接原子的区域之间的边界的标准处理，存在显著误差的固有来源。特别是，在化学上重要的模型区域中的不平衡的电荷分布是这样的问题的潜在来源。我们之前已经提出了ONIOM-CT（具有电荷转移校正的ONIOM），其通过以点电荷的形式施加电势以获得期望的电荷再分布来解决这个问题。费用重新分配的指标取决于用于获取费用的人口分析类型。ONIOM-CT已实施使用Mulliken和Lo browdin人口分析，并已被证明，以提高计算的反应能量为说明性的化学反应。在这项工作中，我们推导并实现了ONIOM-CT的分析梯度，需要求解两组耦合扰动自洽方程，每个模型系统和完整的系统。然而，两者都只需要在低层次的理论，允许一个有效的制定和实施的Mulliken和Lo browdin人口分析。基准和说明性的几何优化已经进行了先前研究的一组反应，涉及一个单一的连接原子之间的区域。此外，我们已经推广了我们的方法，用于处理涉及多个链接原子的模型系统，使应用程序更广泛的问题。两个电荷模型的广义方法进行说明。此外，我们已经研究了一组三个质子转移反应，并证明了显着的改善是通过ONIOM-CT ONIOM使用Mulliken和Lo browdin人口分析。
Hybrid methods such as ONIOM that treat different regions of a large molecule using different methods are widely used to investigate chemical reactions in a variety of materials and biological systems. However, there are inherent sources of significant errors due to the standard treatment of the boundary between the regions using hydrogen link atoms. In particular, an unbalanced charge distribution in the chemically important model region is a potential source of such problems. We have previously suggested ONIOM-CT (ONIOM with charge transfer corrections) which addresses this issue by applying a potential in the form of point charges to obtain a desired charge redistribution. The metric for charge redistribution relies on the type of population analysis used to obtain the charges. ONIOM-CT has been implemented using Mulliken and Löwdin population analyses and has been shown to improve computed reaction energies for illustrative chemical reactions. In this work, we derive and implement the analytic gradients for ONIOM-CT that requires solving two sets of coupled-perturbed self-consistent equations, one each for the model system and the full system. However, both are needed only at the low level of theory, allowing for an efficient formulation and implementation for both Mulliken and Löwdin population analyses. Benchmarking and illustrative geometry optimizations have been carried out for a previously studied set of reactions involving a single link atom between regions. Additionally, we have generalized our method for the treatment of model systems involving multiple link atoms to enable applications for a broader set of problems. The generalized methods are illustrated for both charge models. Furthermore, we have studied a set of three proton transfer reactions and demonstrate that significant improvement is achieved by ONIOM-CT over ONIOM using both Mulliken and Löwdin population analyses.