Physical Chemistry

Accurate prediction of vertical ionization potentials and electron affinities from spin-component scaled CC2 and ADC(2) models

Authors

  • Ahmed Shaalan Alag György Hevesy Doctoral School, Eötvös Loránd University - Hungary ,
  • Dávid P. Jelenfi György Hevesy Doctoral School, Eötvös Loránd University - Hungary ,
  • Attila Tajti Institute of Chemistry, Eötvös Loránd University - Hungary ,
  • Péter G. Szalay Institute of Chemistry, Eötvös Loránd University - Hungary

Abstract

The CC2 and ADC(2) wave function models and their spin-component scaled modifications are adopted for predicting vertical ionization potentials (VIPs) and electron affinities (VEAs). The ionic solutions are obtained as electronic excitations in the continuum orbital formalism, making possible the use of existing, widespread quantum chemistry codes with minimal modifications, in full consistency with the treatment of charge transfer excitations. The performance of different variants is evaluated via benchmark calculations on various sets from previous works, containing small and medium-sized systems, including the nucleobases. It is shown that with the spin-scaled approximate methods, in particular the scaled opposite-spin variant of the ADC(2) method the accuracy of EOM-CCSD is achievable at a fraction of the computational cost, also outperforming many common electron propagator approaches.

Version notes

Updated manuscript after peer review.

Content

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Supplementary material

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SUPPORTING INFORMATION: Accurate prediction of vertical ionization potentials and electron affinities from spin-component scaled CC2 and ADC(2) models
Calculated vertical ionization potentials and electron affinities of the systems benchmarked in this study.