• 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 ...
    • Predictions of Pre-edge Features in Time-Resolved Near-Edge X-ray Absorption Fine Structure Spectroscopy from Hole–Hole Tamm–Dancoff-Approximated Density Functional Theory 

      Hohenstein, Edward G; Yu, Jimmy; Bannwarth, Christoph; Holmgaard List, Nanna; Paul, Alexander Christian; Folkestad, Sarai Dery; Koch, Henrik; Martinez, Todd J. (Journal article, 2021)
      Time-resolved near-edge X-ray absorption fine structure (TR-NEXAFS) spectroscopy is a powerful technique for studying photochemical reaction dynamics with femtosecond time resolution. In order to avoid ambiguity in TR-NEXAFS ...
    • 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 ...
    • Transient Resonant Auger-Meitner Spectra of Photoexcited Thymine 

      Wolf, Thomas J. A.; Paul, Alexander Christian; Folkestad, Sarai Dery; Myhre, Rolf Heilemann; Cryan, James P.; Berrah, Nora; Bucksbaum, Philip H.; Coriani, Sonia; Coslovich, Giacomo; Feifel, Raimund; Martinez, Todd J.; Moeller, Stefan P.; Mucke, Melanie; Obaid, Razib; Plekan, Oksana; Squibb, Richard; Koch, Henrik; Gühr, Markus (Journal article; Peer reviewed, 2021)
      We present the first investigation of excited state dynamics by resonant Auger–Meitner spectroscopy (also known as resonant Auger spectroscopy) using the nucleobase thymine as an example. Thymine is photoexcited in the UV ...