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Title: Hybrid density-functional theory calculations of near-edge x-ray absorption fine-structure spectra: Applications on benzonitrile in gas phase

Journal Article · · Physical Review. A
;  [1];  [1];  [2];  [3]
  1. Laboratoire de Chimie Physique, Matiere et Rayonnement, UMR 7614, Universite Pierre et Marie Curie, 11, rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France)
  2. Department of Physical Sciences, University of Oulu, P. O. Box 3000, FIN-90014, Oulu (Finland)
  3. Theoretical Chemistry, Royal Institute of Technology, AlbaNova, S-106 91 Stockholm (Sweden)

The experimental N(1s) near-edge x-ray-absorption fine-structure spectrum of the benzonitrile molecule in the gas phase shows well separated double peaks with different vibrational profiles. Hybrid density-functional theory calculations reveal that such a separation is a result of the conjugation effect on the nitrogen 2p orbitals and the double spectral peaks can be assigned as the N(1s)-{pi}* out-of-plane and in-plane resonances. The vibrational profiles have been analyzed using a combined transition state theory and linear coupling model. Each profile consists of two different vibrational progressions corresponding to stretching modes and a broad continuum of bending excited states. The use of transition state theory allows identifying the dynamics of the N 1s core excitation. It is found that upon core excitations the C-N bond of the benzonitrile molecule can go from initial linear to final bent structures through different paths. The calculated spectrum is in excellent agreement with experiment.

OSTI ID:
20650078
Journal Information:
Physical Review. A, Vol. 71, Issue 2; Other Information: DOI: 10.1103/PhysRevA.71.022511; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
Country of Publication:
United States
Language:
English