A new method for excited states: Similarity transformed equation-of-motion coupled-cluster theory
A new method for excited states: Similarity transformed equation-of-motion coupled-cluster theory
复制标题
激发态的新方法：相似变换运动方程耦合团簇理论
DOI：
10.1063/1.474000
复制
发表时间：
1997
影响因子：
4.4
通讯作者：
R. Bartlett
中科院分区：
文献类型：
--
作者：
M. Nooijen;R. Bartlett
我们首次应用相似变换运动方程耦合簇方法（STEOM-CC）来计算激发态。 STEOM-CC 理论源自第二量化哈密顿量的相似变换，该变换极大地减少了单激发行列式与更高激发配置之间的耦合。因此，通过仅在单激励空间中对角化变换的哈密顿量，可以获得良好的激励能量近似值。应用STEOM方法获得吡啶分子的价态激发光谱。 STEOM 的精度与当前最先进的方法（如运动方程耦合簇理论和 CASPT2）相当，而与上述方法相比，STEOM 的计算要求非常适中。
We present the first application of the similarity transformed equation-of-motion coupled-cluster method (STEOM-CC) to calculate excited states. STEOM-CC theory arises from a similarity transform of the second quantized Hamiltonian which strongly reduces the coupling between singly excited determinants and more highly excited configurations. Consequently, excitation energies can be obtained to a good approximation by diagonalizing the transformed Hamiltonian in the space of single excitations only. The STEOM method is applied to obtain the valence excitation spectrum of the pyridine molecule. The accuracy of STEOM is shown to be comparable to current state of the art methods like equation-of-motion coupled-cluster theory and CASPT2, whereas the computational requirements of STEOM are very modest compared to the above methods.