Cold and ultracold dynamics of the barrierless D{sup +} + H{sub 2} reaction: Quantum reactive calculations for ∼R{sup −4} long range interaction potentials

Journal Article · Sat Nov 28 04:00:00 EST 2015 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4936144· OSTI ID:22493273

Lara, Manuel ^[1]; Jambrina, P. G.; Aoiz, F. J. ^[2]; Launay, J. -M. ^[3]

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1. Departamento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid (Spain)
2. Departamento de Química Física, Facultad de Química, Universidad Complutense, 28040 Madrid (Spain)
3. Institut de Physique de Rennes, UMR CNRS 6251, Université de Rennes I, F-35042 Rennes (France)

Quantum reactive and elastic cross sections and rate coefficients have been calculated for D{sup +} + H{sub 2} (v = 0, j = 0) collisions in the energy range from 10{sup −8} K (deep ultracold regime), where only one partial wave is open, to 150 K (Langevin regime) where many of them contribute. In systems involving ions, the ∼R{sup −4} behavior extends the interaction up to extremely long distances, requiring a special treatment. To this purpose, we have used a modified version of the hyperspherical quantum reactive scattering method, which allows the propagations up to distances of 10{sup 5} a{sub 0} needed to converge the elastic cross sections. Interpolation procedures are also proposed which may reduce the cost of exact dynamical calculations at such low energies. Calculations have been carried out on the PES by Velilla et al. [J. Chem. Phys. 129, 084307 (2008)] which accurately reproduces the long range interactions. Results on its prequel, the PES by Aguado et al. [J. Chem. Phys. 112, 1240 (2000)], are also shown in order to emphasize the significance of the inclusion of the long range interactions. The calculated reaction rate coefficient changes less than one order of magnitude in a collision energy range of ten orders of magnitude, and it is found in very good agreement with the available experimental data in the region where they exist (10-100 K). State-to-state reaction probabilities are also provided which show that for each partial wave, the distribution of HD final states remains essentially constant below 1 K.

• OSTI ID: 22493273
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 20 Vol. 143; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CROSS SECTIONS
HYDROGEN
INCLUSIONS
INTERACTION RANGE
INTERPOLATION
ION-MOLECULE COLLISIONS
PARTIAL WAVES
POTENTIALS
PROBABILITY
REACTION KINETICS
SCATTERING
TEMPERATURE DEPENDENCE