论文标题
局部旋转旋转：非正交配置相互作用的尺寸一致的方法
Localised Spin Rotations: A Size-Consistent Approach to Non-Orthogonal Configuration Interaction
论文作者
论文摘要
当前的非正交构型相互作用（NOCI）方法通常使用基于化学直觉选择的一组自洽场（SCF）状态。但是，在解离轮廓上跟踪这些SCF状态可能是具有挑战性的，而回收的NOCI状态可能会受到污染。在本文中，我们提出了一种将自旋旋转施加在对称性损坏的UHF（SB-UHF）状态下的方法，以生成NOCI的基础。通过在每个产生的卡宾片段上定位自旋旋转来检查乙烯的解离。我们表明，这给出了对其解离的大小一致的描述，并在所有几何形状上都产生了旋转状态。还使用不同的轨道，即典型的UHF和绝对局部的分子轨道（ALMO）研究了解离。此外，我们证明该方法可用于恢复各种尺寸分子的对称性损坏的SCF波形的自旋对称性，这标志着对现有NOCI方法的改进。
Current Non-Orthogonal Configuration Interaction (NOCI) methods often use a set of Self-Consistent Field (SCF) states selected based on chemical intuition. However, it may be challenging to track these SCF states across a dissociation profile and the NOCI states recovered may be spin contaminated. In this paper, we propose a method of applying spin rotation on symmetry broken UHF (sb-UHF) states to generate a basis for NOCI. The dissociation of ethene was examined by localising spin rotation on each resulting carbene fragment. We show that this gives a size-consistent description of its dissociation and results in spin-pure states at all geometries. The dissociation was also studied with different orbitals, namely canonical UHF and Absolutely Localised Molecular Orbitals (ALMO). Furthermore, we demonstrate that the method can be used to restore spin symmetry of symmetry broken SCF wavefunctions for molecules of various sizes, marking an improvement over existing NOCI methods.
