Hermitian second-order methods for excited electronic states: unitary coupled cluster in comparison with algebraic-diagrammatic construction schemes
Employing an intermediate state representation (ISR) approach, Hermitian second-order methods for the calculation of electronic excitation energies are presented and compared in detail. These comprise the algebraic-diagrammatic construction scheme for the polarization propagator, a hybrid second-ord...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article (Journal) |
| Language: | English |
| Published: |
02 March 2020
|
| In: |
The journal of chemical physics
Year: 2020, Volume: 152, Issue: 9 |
| ISSN: | 1089-7690 |
| DOI: | 10.1063/1.5142354 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1063/1.5142354
|
| Author Notes: | Manuel Hodecker, Dirk R. Rehn and Andreas Dreuw |
| Summary: | Employing an intermediate state representation (ISR) approach, Hermitian second-order methods for the calculation of electronic excitation energies are presented and compared in detail. These comprise the algebraic-diagrammatic construction scheme for the polarization propagator, a hybrid second-order ISR scheme based on traditional coupled-cluster theory as well as two similar approaches based on a unitary coupled-cluster (UCC) ansatz. Although in a strict perturbation-theoretical framework all prove to be identical, differences emerge when the corresponding converged cluster amplitudes are used and depending on how the similarity-transformed UCC Hamiltonian is evaluated. The resulting excitation energies, however, do not significantly differ for systems well described by means of perturbation theory. |
|---|---|
| Item Description: | Gesehen am 31.03.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1089-7690 |
| DOI: | 10.1063/1.5142354 |