• Crossing conditions in coupled cluster theory 

      Kjønstad, Eirik Fadum; Heilemann Myhre, Rolf; Martinez, Todd J.; Koch, Henrik (Journal article; Peer reviewed, 2017)
      We derive the crossing conditions at conical intersections between electronic states in coupled cluster theory and show that if the coupled cluster Jacobian matrix is nondefective, two (three) independent conditions are ...
    • Large-Scale Electron Correlation Calculations: Rank-Reduced Full Configuration Interaction 

      Fales, B Scott; Seritan, Stefan; Settje, Nick F; Levine, Benjamin G; Koch, Henrik; Martinez, Todd J. (Journal article, 2018)
      We present the rank-reduced full configuration interaction (RR-FCI) method, a variational approach for the calculation of extremely large full configuration interaction (FCI) wave functions. In this report, we show that ...
    • Observation of Ultrafast Intersystem Crossing in Thymine by Extreme Ultraviolet Time-Resolved Photoelectron Spectroscopy 

      Wolf, Thomas J. A.; Parrish, Robert M; Myhre, Rolf Heilemann; Martinez, Todd J.; Koch, Henrik; Gühr, Marcus (Journal article; Peer reviewed, 2019)
      We studied the photoinduced ultrafast relaxation dynamics of the nucleobase thymine using gas-phase time-resolved photoelectron spectroscopy. By employing extreme ultraviolet pulses from high harmonic generation for ...
    • Probing ultrafast ππ*/nπ* internal conversion in organic chromophores via K-edge resonant absorption 

      J. A. Wolf, Thomas; Heilemann Myhre, Rolf; P. Cryan, James; Coriani, Sonia; Squibb, Richard; Battistoni, Andrea; Berrah, Nora; Bostedt, Christoph; Bucksbaum, Phil; Coslovich, Giacomo; Feifel, Raimund; J. Gaffney, Kelly; Grilj, Jakob; Martinez, Todd J.; Miyabe, Shungo; Moeller, Stefan P.; Mucke, Melanie; Natan, Adi; Obaid, Razid; Osipov, Timur; Plekan, Oksana; Wang, Song; Koch, Henrik; Gühr, Markus (Journal article; Peer reviewed, 2017)
      Many photoinduced processes including photosynthesis and human vision happen in organic molecules and involve coupled femtosecond dynamics of nuclei and electrons. Organic molecules with heteroatoms often possess an important ...