% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{GomezCarrasco:11459,
      author       = {Gomez-Carrasco, S. and Müller, T. and Köppel, H.},
      title        = {{A}b {I}nitio {S}tudy of the {VUV}-{I}nduced {M}ultistate
                      {P}hotodynamics of {F}ormaldehyde},
      journal      = {The journal of physical chemistry / A},
      volume       = {114},
      issn         = {1089-5639},
      address      = {Washington, DC},
      publisher    = {Soc.},
      reportid     = {PreJuSER-11459},
      pages        = {11436 - 11449},
      year         = {2010},
      note         = {S. Gomez-Carrasco thanks the Alexander von Humboldt
                      Foundation for financial support. The authors are indebted
                      to H. Lischka for useful discussions and to COST ACTION
                      D37/Working Group Photodyn for financial support.},
      abstract     = {Although formaldehyde, H₂CO, has been extensively studied
                      there are still several issues not-well understood,
                      specially regarding its dynamics in the VUV energy range,
                      mainly due to the amount of nonadiabatic effects governing
                      its dynamics. Most of the theoretical work on this molecule
                      has focused on vertical excitation energies of Rydberg and
                      valence states. In contrast to photodissociation processes
                      involving the lowest-lying electronic states below 4.0 eV,
                      there is little known about the photodynamics of the
                      high-lying electronic states of formaldehyde (7-10 eV). One
                      question of particular interest is why the (π, π*)
                      electronic state is invisible experimentally even though it
                      corresponds to a strongly dipole-allowed transition. In this
                      work we present a coupled multisurface 2D photodynamics
                      study of formaldehyde along the CO stretching and the
                      symmetric HCH bending motion, using a quantum time-dependent
                      approach. Potential energy curves along all the vibrational
                      normal modes of formaldehyde have been computed using
                      equation-of-motion coupled cluster including single and
                      double excitations with a quadruply augmented basis set. In
                      the case of the CO stretching coordinate, state-averaged
                      complete active space self-consistent field followed by
                      multireference configuration interaction was used for large
                      values of this coordinate. 2D (for the CO stretching
                      coordinate and the HCH angle) and 3D (including the
                      out-of-plane distortion) potential energy surfaces have been
                      computed for several Rydberg and valence states. Several
                      conical intersections (crossings between potential energy
                      surfaces of the same multiplicity) have been characterized
                      and analyzed and a 2D 5 × 5 diabatic model Hamiltonian has
                      been constructed. Based on this Hamiltonian, electronic
                      absorption spectra, adiabatic and diabatic electronic
                      populations and vibrational densities have been obtained and
                      analyzed. The experimental VUV absorption spectrum in the
                      7-10 eV energy range is well reproduced, including the
                      vibrational structure and the high irregularity in the
                      regime of strong interaction between the (π, π*)
                      electronic state and neighboring Rydberg states.},
      keywords     = {Formaldehyde: chemistry / Photochemical Processes / Quantum
                      Theory / Spectrophotometry, Ultraviolet / Ultraviolet Rays /
                      Formaldehyde (NLM Chemicals) / J (WoSType)},
      cin          = {JSC},
      ddc          = {530},
      cid          = {I:(DE-Juel1)JSC-20090406},
      pnm          = {Scientific Computing (FUEK411) / 411 - Computational
                      Science and Mathematical Methods (POF2-411)},
      pid          = {G:(DE-Juel1)FUEK411 / G:(DE-HGF)POF2-411},
      shelfmark    = {Chemistry, Physical / Physics, Atomic, Molecular $\&$
                      Chemical},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:20931949},
      UT           = {WOS:000283471900010},
      doi          = {10.1021/jp106777z},
      url          = {https://juser.fz-juelich.de/record/11459},
}