A Unique QP Partitioning and Siegert Width Using Real-Valued Continuum-Remover Potential
A Unique QP Partitioning and Siegert Width Using Real-Valued Continuum-Remover Potential
复制标题
使用实值连续体去除势的独特 QP 划分和 Siegert 宽度
DOI：
10.1021/acs.jctc.1c01096
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发表时间：
2022
影响因子：
5.5
通讯作者：
Matsika, Spiridoula
中科院分区：
文献类型：
--
作者：
Sajeev, Y.;Thodika, Mushir;Matsika, Spiridoula
本文提出了一种计算自电离共振能位和衰减宽度的简单、实用的量子化学方法。它结合了L2稳定的共振波函数获得使用实值连续体去除（CR）势[Y。SajeevChem. 2013，587，105-112]和Feshbach投影算子（FPO）分割技术。不同于传统的FPO分割的总波函数到它的共振空间和backgroundspace分量，显式分区的总波函数到它的相互作用区域和非相互作用区域的组件的帮助下，实值连续去除潜在的。该分子系统最初被限制在CR势内，该CR势去除了其共振态嵌入的分子系统的电子连续谱，因此，解开了共振波函数的空间分量作为受限系统的束缚、局部本征态。在空间中表示的分子哈密顿量的本征函数构成一个互补的正交空间。当空间函数与空间耦合产生的能级位移为零时，得到了一个唯一的划分空间，并利用这些划分空间计算了共振宽度.这种新的程序，我们称之为CR-FPO形式主义，形式上是非常简单和直接的实现，但它的应用程序的共振态的模型哈密顿和双激发共振态的原子和分子系统在全CI水平是非常准确的替代相比，非常preciseL 2方法。此外，将CR-FPO方法应用于多参考组态相互作用（MRCI）方法中，并计算了N2-中2 π形共振的能量位置和共振化衰减宽度。
A simple, practical quantum chemical procedure is presented for computing the energy position and the decay width of autoionization resonances. It combines theL2-stabilized resonance wave function obtained using the real-valued continuum-remover (CR) potential [Y. SajeevChem. Phys. Lett.2013,587, 105–112] and the Feshbach projection operator (FPO) partitioning technique. Unlike the conventional FPO partitioning of the total wave function into its resonantspaceand backgroundspacecomponents, an explicit partitioning of the total wave function into its interaction region and noninteraction region components is obtained with the help of real-valued continuum-remover potential. The molecular system is initially confined inside a CR potential which removes the electronic continuum of the molecular system in which its resonance state is embedded and, thus, unravels thespacecomponent of the resonance wave function as a bound, localized eigenstate of the confined system. The eigenfunctions of the molecular Hamiltonian represented in thespaceconstitute a complementary, orthogonalspace. A uniquepartition is obtained when the level-shift of thespacefunction due to its coupling with thespaceis zero, and the resonance width is computed using these unique partitioned spaces. This new procedure, which we refer to as CR-FPO formalism, is formally very simple and straightforward to implement, yet its applications to the resonance state of a model Hamiltonian and to the doubly excited resonance states of atomic and molecular systems at the full-CI level are very accurate as compared to the alternative, very preciseL2methods. In addition, the CR-FPO formalism is implemented in the multireference configuration interaction (MRCI) method, and uses it for calculating the energy position and the autionization decay width of2Πgshape resonance inN2–.