State-to-state rotational transitions in H 2+H 2 collisions at low temperatures

Teck Ghee Lee, N. Balakrishnan, Robert C. Forrey, P. C. Stancil, D. R. Schultz, Gary J. Ferland

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

We present quantum mechanical close-coupling calculations of collisions between two hydrogen molecules over a wide range of energies, extending from the ultracold limit to the superthermal region. The two most recently published potential energy surfaces for the H 2-H 2 complex, the so-called Diep-Johnson (DJ) [J. Chem. Phys. 112, 4465 (2000); 113, 3480 (2000)] and Boothroyd-Martin-Keogh-Peterson (BMKP) [J. Chem. Phys. 116, 666 (2002)] surfaces, are quantitatively evaluated and compared through the investigation of rotational transitions in H 2 +H 2 collisions within rigid rotor approximation. The BMKP surface is expected to be an improvement, approaching chemical accuracy, over all conformations of the potential energy surface compared to previous calculations of H 2-H 2 interaction. We found significant differences in rotational excitation/deexcitation cross sections computed on the two surfaces in collisions between two para-H 2 molecules. The discrepancy persists over a large range of energies from the ultracold regime to thermal energies and occurs for several low-lying initial rotational levels. Good agreement is found with experiment B. Maté et al., [J. Chem. Phys. 122, 064313 (2005)] for the lowest rotational excitation process, but only with the use of the DJ potential. Rate coefficients computed with the BMKP potential are an order of magnitude smaller.

Original languageEnglish (US)
Article number114302
JournalJournal of Chemical Physics
Volume125
Issue number11
DOIs
StatePublished - Oct 2 2006

Fingerprint

rotational states
Potential energy surfaces
collisions
Rigid rotors
Molecules
Thermal energy
Temperature
potential energy
Conformations
Hydrogen
rigid rotors
thermal energy
excitation
molecules
Experiments
energy
cross sections
hydrogen
coefficients
approximation

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

Lee, T. G., Balakrishnan, N., Forrey, R. C., Stancil, P. C., Schultz, D. R., & Ferland, G. J. (2006). State-to-state rotational transitions in H 2+H 2 collisions at low temperatures. Journal of Chemical Physics, 125(11), [114302]. https://doi.org/10.1063/1.2338319
Lee, Teck Ghee ; Balakrishnan, N. ; Forrey, Robert C. ; Stancil, P. C. ; Schultz, D. R. ; Ferland, Gary J. / State-to-state rotational transitions in H 2+H 2 collisions at low temperatures. In: Journal of Chemical Physics. 2006 ; Vol. 125, No. 11.
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Lee, TG, Balakrishnan, N, Forrey, RC, Stancil, PC, Schultz, DR & Ferland, GJ 2006, 'State-to-state rotational transitions in H 2+H 2 collisions at low temperatures', Journal of Chemical Physics, vol. 125, no. 11, 114302. https://doi.org/10.1063/1.2338319

State-to-state rotational transitions in H 2+H 2 collisions at low temperatures. / Lee, Teck Ghee; Balakrishnan, N.; Forrey, Robert C.; Stancil, P. C.; Schultz, D. R.; Ferland, Gary J.

In: Journal of Chemical Physics, Vol. 125, No. 11, 114302, 02.10.2006.

Research output: Contribution to journalArticle

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AU - Lee, Teck Ghee

AU - Balakrishnan, N.

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