Second-order variational coupled-cluster linear-response method: A Hermitian time-dependent theory
Second-order variational coupled-cluster linear-response method: A Hermitian time-dependent theory
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二阶变分耦合簇线性响应方法：埃尔米特瞬态理论
DOI：
10.1103/physreva.83.062503
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发表时间：
2011
影响因子：
2.9
通讯作者：
M. Schuetz
中科院分区：
文献类型：
--
作者：
D. Kats;D. Usvyat;M. Schuetz
给出了根据Moeller-Plesset摄动理论截断的时变分耦合簇（TD）线性响应的形式，即TD-VCC[n]线性响应，其中n表示相应准能量相对于涨落势的阶数。所得到的确定激发能的特征值问题是厄米问题，是简单的tam - dancoff形式。VCC激发能与构型-相互作用单体（CIS）模型的激发能相当，而td - harree - fock方法的Casida方程是其近似值。详细讨论了包含电子相关的最低阶方法TD-VCC响应，并探讨了其与其他二阶方法（如CC2线性响应和二阶代数图构造[ADC(2)]）的关系。
The formalism is presented for the linear response of a time-dependent (TD) variational coupled cluster (VCC), truncated according to Moeller-Plesset perturbation theory, i.e., a TD-VCC[n] linear response, where n denotes the order of the corresponding quasienergy with respect to the fluctuation potential. The resulting eigenvalue problem determining the excitation energies is Hermitian and of the simple Tamm-Dancoff form. The VCC excitation energies are equivalent to those of the configuration-interaction singles (CIS) model, while the Casida equation for the TD-Hartree-Fock approach is an approximation to it. The TD-VCC response, the lowest-order method including electron correlation, is discussed in detail and the relations to other second-order methods, such as the CC2 linear response and the algebraic diagrammatic construction at second order [ADC(2)] are explored.