Cooling of interstellar formaldehyde by collision with helium [electronic resource] : an accurate quantum mechanical calculation
- Published
- Washington, D.C : United States. Energy Research and Development Administration, 1975.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy - Physical Description
- 70 pages : digital, PDF file
- Additional Creators
- Lawrence Berkeley National Laboratory, United States. Energy Research and Development Administration, and United States. Department of Energy. Office of Scientific and Technical Information
Access Online
- Restrictions on Access
- Free-to-read Unrestricted online access
- Summary
- In order to test a collisional pumping model as a mechanism for cooling the 6 cm and 2 cm doublets of interstellar formaldehyde, a quantum mechanical scattering calculation is performed. To obtain the intermolecular interaction between H2CO(1A1) and He(1S) two calculations are performed, a Hartree-Fock (HF) potential surface and a configuration interaction (CI) surface. A basis set of better than ''triple zeta plus polarization'' quality is used to compute the HF portion of the potential energy surface. This portion is highly anisotropic and has a slight attraction arising from induction effects at intermolecular separations around 9 a.u. The HF surface is modified through a series of CI calculations. Correlation is found to have little effect in the strongly anisotropic repulsive region of the interaction potential but dominates the well and long-range regions. The maximum well depth is attained for in-plane approaches of He and lies in the range 35-40°$K for arbitrary theta at center of mass separation of 7.5 a.u. The entire surface is fit to a spherical harmonic expansion to facilitate scattering applications.
- Report Numbers
- E 1.99:lbl--3940
lbl--3940 - Subject(s)
- Dissertation Note
- Thesis. Orig. Receipt Date: 30-JUN-76
- Note
- Published through SciTech Connect.
08/01/1975.
"lbl--3940"
Barbara Jane Garrison. - Funding Information
- W-7405-ENG-48
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