Full-dimensional quantum dynamics of CO in collision with H{sub 2}

Journal Article · Thu Jul 21 04:00:00 EDT 2016 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4958951· OSTI ID:22675920

Yang, Benhui; Stancil, P. C. ^[1]; Balakrishnan, N. ^[2]; Zhang, P. ^[3]; Wang, X.; Bowman, J. M. ^[4]; Forrey, R. C. ^[5]

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1. Department of Physics and Astronomy and the Center for Simulational Physics, The University of Georgia, Athens, Georgia 30602 (United States)
2. Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154 (United States)
3. Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States)
4. Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)
5. Department of Physics, Penn State University, Berks Campus, Reading, Pennsylvania 19610 (United States)

Inelastic scattering computations are presented for collisions of vibrationally and rotationally excited CO with H{sub 2} in full dimension. The computations utilize a newly developed six-dimensional potential energy surface (PES) and the previously reported four-dimensional V12 PES [P. Jankowski et al., J. Chem. Phys. 138, 084307 (2013)] and incorporate full angular-momentum coupling. At low collision energies, pure rotational excitation cross sections of CO by para-, ortho-, and normal-H{sub 2} are calculated and convolved to compare with recent measurements. Good agreement with the measured data is shown except for j{sub 1} = 0 → 1 excitation of CO for very low-energy para-H{sub 2} collisions. Rovibrational quenching results are presented for initially excited CO(v{sub 1}j{sub 1}) levels with v{sub 1} = 1, j{sub 1} = 1–5 and v{sub 1} = 2, j{sub 1} = 0 for collisions with para-H{sub 2} (v{sub 2} = 0, j{sub 2} = 0) and ortho-H{sub 2} (v{sub 2} = 0, j{sub 2} = 1) over the kinetic energy range 0.1–1000 cm{sup −1}. The total quenching cross sections are found to have similar magnitudes, but increase (decrease) with j{sub 1} for collision energies above ∼300 cm{sup −1} (below ∼10 cm{sup −1}). Only minor differences are found between para- and ortho-H{sub 2} colliders for rovibrational and pure rotational transitions, except at very low collision energies. Likewise, pure rotational deexcitation of CO yields similar cross sections for the v{sub 1} = 0 and v{sub 1} = 1 vibrational levels, while rovibrational quenching from v{sub 1} = 2, j{sub 1} = 0 is a factor of ∼5 larger than that from v{sub 1} = 1, j{sub 1} = 0. Details on the PES, computed at the CCSD(T)/aug-cc-pV5Z level, and fitted with an invariant polynomial method, are also presented.

• OSTI ID: 22675920
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 3 Vol. 145; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CALCULATION METHODS
COLLISIONS
DYNAMICS
EXCITATION
HYDROGEN
KINETIC ENERGY
POTENTIAL ENERGY
QUENCHING
TOTAL CROSS SECTIONS