Assessing the Performances of CASPT2 and NEVPT2 for Vertical Excitation Energies.

  title={Assessing the Performances of CASPT2 and NEVPT2 for Vertical Excitation Energies.},
  author={Rudraditya Sarkar and Pierre-François Loos and Martial Boggio‐Pasqua and Denis Jacquemin},
  journal={Journal of chemical theory and computation},
Methods able to simultaneously account for both static and dynamic electron correlations have often been employed, not only to model photochemical events but also to provide reference values for vertical transition energies, hence allowing benchmarking of lower-order models. In this category, both the complete-active-space second-order perturbation theory (CASPT2) and the N-electron valence state second-order perturbation theory (NEVPT2) are certainly popular, the latter presenting the… 
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