论文标题
过渡潜力耦合集群II：核心轨道职业数的优化
Transition-Potential Coupled Cluster II: Optimization of the Core Orbital Occupation Number
论文作者
论文摘要
计算核心孔光谱法（特别是X射线吸收）中轨道松弛的问题一直是方法的主要问题，例如与单打和双打（EOM-CCSD）（EOM-CCSD）等运动偶联群集。通过使用具有分数核心职业编号的参考轨道轨道对轨道放松的明确处理，利用了过渡潜力耦合群集（TP-CC）方法来解决此问题。由于原子电荷和能量尺度的差异，针对TP-CCSD和XTP-CCSD方法的分数职业参数$λ$的值均以特定于元素特定的方式优化。此外，对使用优化参数进行TP-CCSD计算，以针对气相腺嘌呤和胸胺的K边缘吸收光谱进行。与EOM-CCSD相比，TP-CCSD很好地重现了价区域，并且需要较小的总能量转移，同时也改善了几个吸收峰的相对位置和强度。
The issue of orbital relaxation in computational core-hole spectroscopy, specifically x-ray absorption, has been a major problem for methods such as equation-of-motion coupled cluster with singles and doubles (EOM-CCSD). The transition-potential coupled cluster (TP-CC) method is utilized to address this problem by including an explicit treatment of orbital relaxation via the use of reference orbitals with a fractional core occupation number. The value of the fractional occupation parameter $λ$ was optimized for both TP-CCSD and XTP-CCSD methods in an element-specific manner due to the differences in atomic charge and energy scale. Additionally, TP-CCSD calculations using the optimized parameters were performed for the K-edge absorption spectra of gas-phase adenine and thymine. TP-CCSD reproduces the valence region well and requires smaller overall energy shifts in comparison to EOM-CCSD, while also improving on the relative position and intensities of several absorption peaks.
