论文标题
通过将核心三重激发纳入相似性转化的EOM理论中，精确核心激发状态
Accurate core-excited states via inclusion of core triple excitations in similarity-transformed EOM theory
论文作者
论文摘要
核心电子激发后轨道松弛的现象是核心孔光谱镜的线性反应处理中的一个主要问题。我们不是通过激发态的直接动态相关性通过动作耦合群集理论（EOMEE-CC）来解决放松，而是扩展了仅通过在内的核心分离分离（CVS）和较量的核心核心核心核心核心核心核心来扩展替代性相似性转换方程式耦合群集理论（STEOMEE-CC）。与完全CVS-Eomee-CCSD和未修饰的CVS-Steomee-CCSD相比，这种新方法CVS-SteomeE-CCSD+CT可显着改善CVS-Eomee-CCSD和未修饰的CVS-Steomee-CCSD，与全CVS-EOM-CCSDT相比，一组小分子的K-Edge核心激素能量。绝对和相对（移位）峰位置的改善几乎与过渡电位耦合簇（TP-CC）一样好，其中包括明确的轨道弛豫处理，以及CVS-Eomee-CCSD*，其中包括三重激发的扰动治疗。
The phenomenon of orbital relaxation upon excitation of core electrons is a major problem in the linear-response treatment of core-hole spectroscopies. Rather than addressing relaxation through direct dynamical correlation of the excited state via equation-of-motion coupled cluster theory (EOMEE-CC), we extend the alternative similarity-transformed equation-of-motion coupled cluster theory (STEOMEE-CC) by including the core-valence separation (CVS) and correlation of triple excitations only within the calculation of core ionization energies. This new method, CVS-STEOMEE-CCSD+cT, significantly improves on CVS-EOMEE-CCSD and unmodified CVS-STEOMEE-CCSD when compared to full CVS-EOM-CCSDT for K-edge core-excitation energies of a set of small molecules. The improvement in both absolute and relative (shifted) peak positions is nearly as good as for transition-potential coupled cluster (TP-CC), which includes an explicit treatment of orbital relaxation, and CVS-EOMEE-CCSD*, which includes a perturbative treatment of triple excitations.
