论文标题
迈向分子电子结构的近乎脱颖而出的溶液：全耦合群集还原，二阶扰动校正
Towards near-exact solutions of molecular electronic structure: Full coupled-cluster reduction with a second-order perturbative correction
论文作者
论文摘要
我们引入了最近开发的全耦合群集还原（FCCR）的新的增强改编，其二阶扰动校正缩写为FCCR（2）。 FCCR是一种选定的耦合群集扩展，旨在最佳地减少高级激发的激发歧管和换向器膨胀，以以尺寸扩展的方式获得电子Schrodinger方程的准确溶液。目前的FCCR（2）可以通过FCCR投影歧管的互补空间从二阶扰动校正$ e^{（2）} $估算FCCR的残差相关性。 $ e^{（2）} $与FCCR（2）的能量之间的线性关系允许对具有强电子相关性的各种分子进行准确估计。该方法的潜力是使用具有挑战性的情况来证明的，例如苯分子在平衡和拉伸几何形状中的基态电子能以及过渡金属复合物的异构化能量，[Cu（NH $ _3 $）] $ _ 2 $ _ 2 $ o _ $ o $ _2 $ _2 $ _2 $^{2+} $。
We introduce a new augmented adaptation of the recently developed full coupled-cluster reduction (FCCR) with a second-order perturbative correction, abbreviated as FCCR(2). FCCR is a selected coupled-cluster expansion aimed at optimally reducing the excitation manifold and commutator expansions for high-rank excitations to obtain accurate solutions of the electronic Schrodinger equation in a size-extensive manner. The present FCCR(2) enables the estimation of the residual correlation of FCCR by the second-order perturbative correction $E^{(2)}$ from the complementary space of the FCCR projection manifold. The linear relationship between $E^{(2)}$ and the energy of FCCR(2) allows accurate estimates of near-exact energies for a wide variety of molecules with strong electron correlations. The potential of the method is demonstrated using challenging cases, such as the ground state electronic energy of the benzene molecule in equilibrium and stretched geometries, and the isomerization energy of the transition metal complex, [Cu(NH$_3$)]$_2$O$_2$$^{2+}$.
