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Title: Probing non-adiabatic conical intersections using absorption, spontaneous Raman, and femtosecond stimulated Raman spectroscopy

We present the time-frame calculated photoabsorption spectrum (ABS), spontaneous Raman excitation profile (REP), femtosecond stimulated Raman spectroscopy (FSRS) spectrum, and femtosecond stimulated Raman excitation profile (FSREP) results of a two-mode and three-mode, three-electronic-states model Hamiltonians containing conical intersections (CIs) along its two upper diabatic electronic states, e{sub 1} (dark) and e{sub 2} (bright), with and without coupling (nonadiabatic dynamics) along an asymmetric mode. For every electronic state in each model, there is one coupling mode and the rest of the modes are symmetric tuning modes. The CI appears in the Hamiltonian as off-diagonal entries to the potential term that couple the two upper states, in the form of a linear function of the coupling mode. We show that: (a) the ABS, REP, and FSREP for Stokes and anti-Stokes lines contain similar information about the e{sub 1} and e{sub 2} vibrational bands, (b) the FSRS spectra feature narrow stationary peaks and broader moving peaks contributed by the different resonant components of the third-order polarization terms from perturbation theory, and (c) a relatively strong and narrow stationary band of the allowed first overtone of the asymmetric coupling mode is observed in the Stokes FSREP in the e{sub 1} energy region with couplingmore » to e{sub 2}.« less
Authors:
;  [1]
  1. School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore)
Publication Date:
OSTI Identifier:
22253757
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 23; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION; COUPLING; EXCITATION; HAMILTONIANS; PERTURBATION THEORY; POLARIZATION; PROBES; RAMAN SPECTROSCOPY; SPECTRA; VIBRATIONAL STATES