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Title: Automatic generation of active coordinates for quantum dynamics calculations: Application to the dynamics of benzene photochemistry

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.2839607· OSTI ID:21104011
; ; ;  [1];  [2];  [3]
  1. Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ (United Kingdom)
  2. School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)
  3. Institut de Quimica Computacional and Departament de Quimica, Universitat de Girona, E-17071 Girona (Spain)

A new practical method to generate a subspace of active coordinates for quantum dynamics calculations is presented. These reduced coordinates are obtained as the normal modes of an analytical quadratic representation of the energy difference between excited and ground states within the complete active space self-consistent field method. At the Franck-Condon point, the largest negative eigenvalues of this Hessian correspond to the photoactive modes: those that reduce the energy difference and lead to the conical intersection; eigenvalues close to 0 correspond to bath modes, while modes with large positive eigenvalues are photoinactive vibrations, which increase the energy difference. The efficacy of quantum dynamics run in the subspace of the photoactive modes is illustrated with the photochemistry of benzene, where theoretical simulations are designed to assist optimal control experiments.

OSTI ID:
21104011
Journal Information:
Journal of Chemical Physics, Vol. 128, Issue 12; Other Information: DOI: 10.1063/1.2839607; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
Country of Publication:
United States
Language:
English