论文标题
二阶扰动理论能否准确预测开放壳分子的电子密度？自洽的重要性
Can second-order perturbation theory accurately predict electron density of open-shell molecules? The importance of self-consistency
论文作者
论文摘要
电子密度分布在预测分子特性中起着至关重要的作用。这也是一个简单的观察，可以从哪种机器学习模型中得出用于分子电子结构的模型。在目前的工作中，我们介绍了我们最近开发的一体Møller-Plesset二阶扰动（OBMP2）理论的表现。在OBMP2中，使用规范转换得出了有效的一体哈密顿量，包括MP2水平的动态相关性，然后是累积近似。我们评估了三组开放式系统的电子密度和相关特性：原子及其离子，主组自由基和卤素调光器。我们发现，在此处考虑的所有情况下，OBMP2都优于标准MP2和密度功能理论，并且其准确性可与耦合群集单打和双打（CCSD）相媲美，这是一种高级方法。因此，OBMP2被认为是预测开放壳分子准确电子密度的有效方法。
Electron density distribution plays an essential role in predicting molecular properties. It is also a simple observable from which machine-learning models for molecular electronic structure can be derived. In the present work, we present the performance of the one-body Møller-Plesset second-order perturbation (OBMP2) theory that we have recently developed. In OBMP2, an effective one-body Hamiltonian including dynamic correlation at the MP2 level is derived using the canonical transformation followed by the cumulant approximation. We evaluate electron density and related properties of three groups of open-shell systems: atoms and their ions, main-group radicals, and halogen dimmers. We find that OBMP2 outperforms standard MP2 and density functional theory in all cases considered here, and its accuracy is comparable to coupled-cluster singles and doubles (CCSD), a higher-level method. OBMP2 is thus believed to be an effective method for predicting the accurate electron density of open-shell molecules.
