Full dimensional Franck-Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X] [superscript 1Σ[+ over g] transition. I. Method for calculating polyatomic linear—bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene

Franck-Condon vibrational overlap integrals for the [~ over A] [superscript 1]A[subscript u] — [~ over X [superscript 1]Σ[+ over g] transition in acetylene have been calculated in full dimension in the harmonic normal mode basis. The calculation uses the method of generating functions first develope...

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Main Author: Park, Barratt
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: American Institute of Physics (AIP) 2015
Online Access:http://hdl.handle.net/1721.1/96882
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author Park, Barratt
author2 Massachusetts Institute of Technology. Department of Chemistry
author_facet Massachusetts Institute of Technology. Department of Chemistry
Park, Barratt
author_sort Park, Barratt
collection MIT
description Franck-Condon vibrational overlap integrals for the [~ over A] [superscript 1]A[subscript u] — [~ over X [superscript 1]Σ[+ over g] transition in acetylene have been calculated in full dimension in the harmonic normal mode basis. The calculation uses the method of generating functions first developed for polyatomic Franck-Condon factors by Sharp and Rosenstock [J. Chem. Phys.41(11), 3453–3463 (1964)], and previously applied to acetylene by Watson [J. Mol. Spectrosc.207(2), 276–284 (2001)] in a reduced-dimension calculation. Because the transition involves a large change in the equilibrium geometry of the electronic states, two different types of corrections to the coordinate transformation are considered to first order: corrections for axis-switching between the Cartesian molecular frames and corrections for the curvilinear nature of the normal modes at large amplitude. The angular factor in the wavefunction for the out-of-plane component of the trans bending mode, ν[′′ over 4], is treated as a rotation, which results in an Eckart constraint on the polar coordinates of the bending modes. To simplify the calculation, the other degenerate bending mode, ν[′′ over 5], is integrated in the Cartesian basis and later transformed to the constrained polar coordinate basis, restoring the conventional v and l quantum numbers. An updated [~ over A]-state harmonic force field obtained recently in the R. W. Field research group is evaluated. The results for transitions involving the gerade vibrational modes are in qualitative agreement with experiment. Calculated results for transitions involving ungerade modes are presented in Paper II of this series [G. B. Park, J. H. Baraban, and R. W. Field, “Full dimensional Franck–Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X [superscript 1]Σ[+ over g] transition. II. Vibrational overlap factors for levels involving excitation in ungerade modes,” J. Chem. Phys.141, 134305 (2014)].
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spelling mit-1721.1/968822022-09-28T15:41:17Z Full dimensional Franck-Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X] [superscript 1Σ[+ over g] transition. I. Method for calculating polyatomic linear—bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene Park, Barratt Massachusetts Institute of Technology. Department of Chemistry Park, Barratt Park, Barratt Franck-Condon vibrational overlap integrals for the [~ over A] [superscript 1]A[subscript u] — [~ over X [superscript 1]Σ[+ over g] transition in acetylene have been calculated in full dimension in the harmonic normal mode basis. The calculation uses the method of generating functions first developed for polyatomic Franck-Condon factors by Sharp and Rosenstock [J. Chem. Phys.41(11), 3453–3463 (1964)], and previously applied to acetylene by Watson [J. Mol. Spectrosc.207(2), 276–284 (2001)] in a reduced-dimension calculation. Because the transition involves a large change in the equilibrium geometry of the electronic states, two different types of corrections to the coordinate transformation are considered to first order: corrections for axis-switching between the Cartesian molecular frames and corrections for the curvilinear nature of the normal modes at large amplitude. The angular factor in the wavefunction for the out-of-plane component of the trans bending mode, ν[′′ over 4], is treated as a rotation, which results in an Eckart constraint on the polar coordinates of the bending modes. To simplify the calculation, the other degenerate bending mode, ν[′′ over 5], is integrated in the Cartesian basis and later transformed to the constrained polar coordinate basis, restoring the conventional v and l quantum numbers. An updated [~ over A]-state harmonic force field obtained recently in the R. W. Field research group is evaluated. The results for transitions involving the gerade vibrational modes are in qualitative agreement with experiment. Calculated results for transitions involving ungerade modes are presented in Paper II of this series [G. B. Park, J. H. Baraban, and R. W. Field, “Full dimensional Franck–Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X [superscript 1]Σ[+ over g] transition. II. Vibrational overlap factors for levels involving excitation in ungerade modes,” J. Chem. Phys.141, 134305 (2014)]. United States. Dept. of Energy. Office of Basic Energy Sciences (Grant DE-FG0287ER13671) 2015-05-04T12:54:21Z 2015-05-04T12:54:21Z 2014-10 2014-05 Article http://purl.org/eprint/type/JournalArticle 0021-9606 1089-7690 http://hdl.handle.net/1721.1/96882 Park, G. Barratt. “Full Dimensional Franck-Condon Factors for the Acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X] [superscript 1Σ[+ over g] Transition. I. Method for Calculating Polyatomic Linear—bent Vibrational Intensity Factors and Evaluation of Calculated Intensities for the Gerade Vibrational Modes in Acetylene.” The Journal of Chemical Physics 141, no. 13 (October 7, 2014): 134304. © 2014 AIP Publishing LLC en_US http://dx.doi.org/10.1063/1.4896532 The Journal of Chemical Physics Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Institute of Physics (AIP) Park
spellingShingle Park, Barratt
Full dimensional Franck-Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X] [superscript 1Σ[+ over g] transition. I. Method for calculating polyatomic linear—bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene
title Full dimensional Franck-Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X] [superscript 1Σ[+ over g] transition. I. Method for calculating polyatomic linear—bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene
title_full Full dimensional Franck-Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X] [superscript 1Σ[+ over g] transition. I. Method for calculating polyatomic linear—bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene
title_fullStr Full dimensional Franck-Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X] [superscript 1Σ[+ over g] transition. I. Method for calculating polyatomic linear—bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene
title_full_unstemmed Full dimensional Franck-Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X] [superscript 1Σ[+ over g] transition. I. Method for calculating polyatomic linear—bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene
title_short Full dimensional Franck-Condon factors for the acetylene [~ over A] [superscript 1]A[subscript u] — [~ over X] [superscript 1Σ[+ over g] transition. I. Method for calculating polyatomic linear—bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene
title_sort full dimensional franck condon factors for the acetylene over a superscript 1 a subscript u over x superscript 1σ over g transition i method for calculating polyatomic linear bent vibrational intensity factors and evaluation of calculated intensities for the gerade vibrational modes in acetylene
url http://hdl.handle.net/1721.1/96882
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