@article{GaebelBeinMathaueretal.2021,
  author    = {Gaebel, Tina and Bein, Daniel and Mathauer, Daniel and Utecht, Manuel and Palmer, Richard E. and Klamroth, Tillmann},
  title     = {Nonlocal STM manipulation of chlorobenzene on Si(111)-7 x 7},
  series = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  volume    = {125},
  journal   = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  number    = {22},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1932-7447},
  doi       = {10.1021/acs.jpcc.1c02612},
  pages     = {12175 -- 12184},
  year      = {2021},
  abstract  = {We use quantum chemical cluster models together with constrained density STM Ph CI functional theory (DFT) and ab initio molecular dynamics (AIMD) for open system to simulate tip and rationalize nonlocal scanning tunneling microscope (STM) manipulation experiments for Philh ci chlorobenzene (PhCl) on a Si(111)-7 X 7 surface. We consider three different processes, namely, the electron-induced dissociation of the carbon-chlorine bond for physisorbed PhCl molecules at low temperatures and the electron- or hole-induced desorption of chemisorbed PhCl at 300 K. All processes can be induced nonlocally, i.e., up to several nanometers (nm) away from the injection site, in STM experiments. We rationalize and explain the experimental findings regarding the STM-induced dissociation using constrained DFT. The coupling of STM-induced ion resonances to nuclear degrees of freedom is simulated with AIMD using the Gadzuk averaging approach for open systems. From this data, we predict a 4 fs lifetime for the cationic resonance. For the anion model, desorption could not be observed. In addition, the same cluster models are used for transition-state theory calculations, which are compared to and validated against time-lapse STM experiments.},
  language  = {en}
}
@article{UtechtGaebelKlamroth2018,
  author    = {Utecht, Manuel Martin and Gaebel, Tina and Klamroth, Tillmann},
  title     = {Desorption induced by low energy charge carriers on Si(111)-7 x 7},
  series = {Journal of computational chemistry : organic, inorganic, physical, biological},
  volume    = {39},
  journal   = {Journal of computational chemistry : organic, inorganic, physical, biological},
  number    = {30},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0192-8651},
  doi       = {10.1002/jcc.25607},
  pages     = {2517 -- 2525},
  year      = {2018},
  abstract  = {We use clusters for the modeling of local ion resonances caused by low energy charge carriers in STM-induced desorption of benzene derivates from Si(111)-7 x 7. We perform Born-Oppenheimer molecular dynamics for the charged systems assuming vertical transitions to the charged states at zero temperature, to rationalize the low temperature activation energies, which are found in experiment for chlorobenzene. Our calculations suggest very similar low temperature activation energies for toluene and benzene. For the cationic resonance transitions to physisorption are found even at 0 K, while the anion remains chemisorbed during the propagations. Further, we also extend our previous static quantum chemical investigations to toluene and benzene. In addition, an in depth analysis of the ionization potentials and electron affinities, which are used to estimate resonance energies, is given.},
  language  = {en}
}
@article{KroenerGaebel2015,
  author    = {Kr{\"o}ner, Dominik and Gaebel, Tina},
  title     = {Circular Dichroism in Mass Spectrometry: Quantum Chemical Investigations for the Differences between (R)-3-Methylcyclopentanone and Its Cation},
  series = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory},
  volume    = {119},
  journal   = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory},
  number    = {34},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1089-5639},
  doi       = {10.1021/acs.jpca.5b05247},
  pages     = {9167 -- 9177},
  year      = {2015},
  abstract  = {In mass spectrometry enantiomers can be distinguished by multiphoton ionization employing circular polarized laser pulses. The circular dichroism (CD) is detected from the normalized difference in the ion yield after excitation with light of opposite handedness. While there are cases in which fragment and parent ions exhibit the same sign of the CD in the ion yield, several experiments show that they might also differ in sign and magnitude. Supported by experimental observations it has been proposed that the parent ion, once it has been formed, is further excited by the laser, which may result in a change of the CD in the ion yield of the formed fragments compared to the parent ion. To gain a deeper insight in possible excitation pathways we calculated and compared the electronic CD absorption spectra of neutral and cationic (R)-3-methylcyclopentanone, applying density functional theory. In addition, electron wavepacket dynamics were used to compare the CD of one- and two-photon transitions. Our results support the proposed subsequent excitation of the parent ion as a possible origin of the difference of the CD in the ion yield between parent ion and fragments.},
  language  = {en}
}