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Title: Collisional Quenching of Highly Excited H2 due to H2 Collisions

Journal Article · · The Astrophysical Journal (Online)
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [2];  [3]; ORCiD logo [4]
  1. Univ. of Georgia, Athens, GA (United States)
  2. Univ. of Nevada, Las Vegas, NV (United States)
  3. Univ. of Nevada, Las Vegas, NV (United States); The Pennsylvania State Univ. College of Medicine, Hershey, PA (United States)
  4. Penn State Univ., Reading, PA (United States)
+ Show Author Affiliations

Rate coefficients for pure rotational quenching in H2(ν 1 = 0, j 1) + H2(ν 2 = 0, j 2) collisions from initial levels of j 1 = 2–31 (j 2 = 0 or 1) to all lower rotational levels are presented. Here, we carried out extensive quantum mechanical close-coupling calculations based on a recently published H2–H2 potential energy surface (PES) developed by Patkowski et al. that has been demonstrated to be more reliable than previous work. Rotational transition cross sections with initial levels of j 1 = 2–14, 18, 19, 24, and 25 were computed for energies ranging from 10-6 to 1000 cm-1, while the coupled-states approximation was adopted from 2000 to 20,000 cm-1. The corresponding rate coefficients were calculated for the temperature range 10-5 ≤ T ≤ 10,000 K. Scaling methods based on the ultra-cold data (10-5–1 K) were used to estimate rate coefficients for all other intermediate rotational states. Comparisons with previous work that adopted different PESs show small discrepancies at high temperatures and in low-energy resonance regions. The astrophysical applications of the current results are briefly discussed, including the rotational H2 critical densities due to para-H2 and ortho-H2 collisions.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
Sponsoring Organization:
USDOE Office of Science (SC)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1565709
Journal Information:
The Astrophysical Journal (Online), Journal Name: The Astrophysical Journal (Online) Journal Issue: 2 Vol. 862; ISSN 1538-4357
Publisher:
Institute of Physics (IOP)Copyright Statement
Country of Publication:
United States
Language:
English

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Cited By (4)

Matrix formulation of the energy exchange problem of multi-level systems and the code FRIGUS journal October 2019
Rotational quenching of HD induced by collisions with H2 molecules journal June 2019
Rotational Quenching of HD in Collisions with H 2 : Resolving Discrepancies for Low-lying Rotational Transitions journal October 2018
Platinum, gold, and silver standards of intermolecular interaction energy calculations journal August 2019

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