Calculation of excited-state properties using general coupled-cluster and configuration-interaction models |
| |
Authors: | Kállay Mihály Gauss Jürgen |
| |
Institution: | Institut für Physikalische Chemie, Universit?t Mainz, D-55099 Mainz, Germany. kallay@uni-mainz.de |
| |
Abstract: | Using string-based algorithms excitation energies and analytic first derivatives for excited states have been implemented for general coupled-cluster (CC) models within CC linear-response (LR) theory which is equivalent to the equation-of-motion (EOM) CC approach for these quantities. Transition moments between the ground and excited states are also considered in the framework of linear-response theory. The presented procedures are applicable to both single-reference-type and multireference-type CC wave functions independently of the excitation manifold constituting the cluster operator and the space in which the effective Hamiltonian is diagonalized. The performance of different LR-CC/EOM-CC and configuration-interaction approaches for excited states is compared. The effect of higher excitations on excited-state properties is demonstrated in benchmark calculations for NH(2) and NH(3). As a first application, the stationary points of the S(1) surface of acetylene are characterized by high-accuracy calculations. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|