Benchmarking Second Order Methods for the Calculation of Vertical Electronic Excitation Energies: Valence and Rydberg States in Polycyclic Aromatic Hydrocarbons

Abstract

The performance of the six second order linear response methods RPA(D), SOPPA, SOPPA(CCSD), CIS(D), CC2, and CCSD, which include either noniterative or iterative doubles contributions, has been studied in calculations of vertical excitation energies. The benchmark set consisted of 39 valence and 76 Rydberg states of benzene and five polycyclic aromatic hydrocarbons. As reference values we have used the results of the corresponding calculations with the third order method CCSDR(3), which includes noniterative triples contributions. In addition we have also carried out equivalent calculations at the level of the random phase approximation as well as with the configuration interaction singles and multireference configuration interaction singles and doubles methods.

Symmetry, vibrational energy redistribution and vibronic coupling: The internal conversion processes of cycloketones

“…57 For cyclopentanone, the band maximum and origin again coincide at 6.95 eV, however, the vertical transition energy from electron ionization is again slightly higher at 7.2 eV. 52 Comparing to the calculated energies, the CC2 values are generally too low for the Rydberg states as seen also for other systems, 60 which is somewhat overcompensated for by CCSD. It can be observed that CCSDR(3) makes a small counter-correction of around 0.1 eV to the CCSD values.…”

Quantum Chemical Description of Absorption Properties and Excited‐State Processes in Photosynthetic Systems

“…[64], and a benchmark study of these methods can be found in ref. [65]. In the context of ADC(2), [66] two variants can be distinguished: the strict ADC(2)-s version, which does not include couplings between doubly excited states, and the extended ADC(2)-x version, which shows a less favorable scaling behavior with system size but includes these couplings to first order.…”

Excitation spectra of aromatic molecules within a real-spaceGW-BSE formalism: Role of self-consistency and vertex corrections

“…For benzene, naphthalene, and thiophene, our self-consistent and mixed GW -BSE calculations have fairly good agreement best previous theoretical values, which are computed including contributions from singles, doubles, and triples excitations. [80][81][82] The mean absolute difference across these three molecules is 0.78 eV for G 0 W 0 -BSE, 0.68 eV for G 0 W 0 Γ LDA , 0.14 for mixed GW -BSE, 0.25 for QSGW -BSE, 0.24 for QSGW Γ LDA -BSE, and 0.25 for TDLDA. For 1,2,5-thiadiazole, the cited calculation only include singles and doubles excitations, 83 and the mean absolute difference is 1.26 eV for G 0 W 0 -BSE, 1.14 eV for G 0 W 0 Γ LDA , 0.58 eV for mixed GW -BSE, 0.33 eV for QSGW -BSE, 0.29 for GW Γ LDA -BSE, and 0.61 for TDLDA.…”