论文标题
主动空间对2电子降低密度矩阵理论，以实现强相关性
Active Space Pair 2-Electron Reduced Density Matrix Theory for Strong Correlation
论文作者
论文摘要
在对近似值内有活性轨道相关的，在2-电子还原密度矩阵（2-RDM）的活跃空间变化计算被得出并实现。两对近似仅考虑了波函数的双重占用配置，该配置可以以$ \ Mathcal {O}（r^3）$的计算成本来计算2-RDM。使用对活跃空间配置相互作用（PASCI）方法和配对活动空间自我一致字段（PARSCF）方法进行计算。后者包括通过单一变换混合活性轨道和非活性轨道的混合。活性空间对2-RDM方法应用于氮分子，P-Benzyne Diradical，一种新合成的Biscobalt络合物和氮酶辅助因子Femoco。在[120,120]活性空间中处理Femoco分子。这些系统中的每个系统都回收了分数职业，表明强烈电子相关的检测和恢复。
An active space variational calculation of the 2-electron reduced density matrix (2-RDM) is derived and implemented where the active orbitals are correlated within the pair approximation. The pair approximation considers only doubly occupied configurations of the wavefunction which enables the calculation of the 2-RDM at a computational cost of $\mathcal{O}(r^3)$. Calculations were performed both with the pair active space configuration interaction (PASCI) method and the pair active space self consistent field (PASSCF) method. The latter includes a mixing of the active and inactive orbitals through unitary transformations. The active-space pair 2-RDM method is applied to the nitrogen molecule, the p-benzyne diradical, a newly synthesized BisCobalt complex, and the nitrogenase cofactor FeMoco. The FeMoco molecule is treated in a [120,120] active space. Fractional occupations are recovered in each of these systems, indicating the detection and recovery of strong electron correlation.
