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Title: Symmetry and the geometric phase in ultracold hydrogen-exchange reactions

Authors:
ORCiD logo [1];  [1]; ORCiD logo [1];  [2]
  1. Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154, USA
  2. Theoretical Division (T-1, MS B221), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1375071
Grant/Contract Number:
20170221ER
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 147; Journal Issue: 7; Related Information: CHORUS Timestamp: 2018-02-15 02:27:30; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Croft, J. F. E., Hazra, J., Balakrishnan, N., and Kendrick, B. K. Symmetry and the geometric phase in ultracold hydrogen-exchange reactions. United States: N. p., 2017. Web. doi:10.1063/1.4998226.
Croft, J. F. E., Hazra, J., Balakrishnan, N., & Kendrick, B. K. Symmetry and the geometric phase in ultracold hydrogen-exchange reactions. United States. doi:10.1063/1.4998226.
Croft, J. F. E., Hazra, J., Balakrishnan, N., and Kendrick, B. K. 2017. "Symmetry and the geometric phase in ultracold hydrogen-exchange reactions". United States. doi:10.1063/1.4998226.
@article{osti_1375071,
title = {Symmetry and the geometric phase in ultracold hydrogen-exchange reactions},
author = {Croft, J. F. E. and Hazra, J. and Balakrishnan, N. and Kendrick, B. K.},
abstractNote = {},
doi = {10.1063/1.4998226},
journal = {Journal of Chemical Physics},
number = 7,
volume = 147,
place = {United States},
year = 2017,
month = 8
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on August 15, 2018
Publisher's Accepted Manuscript

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

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  • The role of the geometric phase effect on chemical reaction dynamics is explored by examining the hydrogen exchange process in the fundamental H+HD reaction. Results are presented for vibrationally excited HD molecules in the v = 4 vibrational level and for collision energies ranging from 1 μK to 100 K. It is found that, for collision energies below 3 K, inclusion of the geometric phase leads to dramatic enhancement or suppression of the reaction rates depending on the final quantum state of the HD molecule. The effect was found to be the most prominent for rotationally resolved integral and differential cross sections but it persists to a lesser extent in the vibrationally resolved and total reaction rate coefficients. However, no significant GP effect is present in the reactive channel leading to the D+H 2 product or in the D+H 2more » $$(v=4,j=0)\,\to $$ HD+H reaction. A simple interference mechanism involving inelastic (nonreactive) and exchange scattering amplitudes is invoked to account for the observed GP effects. The computed results also reveal a shape resonance in the H+HD reaction near 1 K and the GP effect is found to influence the magnitude of the resonant part of the cross section. In conclusion, experimental detection of the resonance may allow a sensitive probe of the GP effect in the H+HD reaction.« less
  • The results of accurate quantum reactive scattering calculations for the D + HD(v = 4, j = 0)more » $$\to $$ D + HD($$v^{\prime} $$, $$j^{\prime} $$), D + HD(v = 4, j = 0) $$\to $$ H + D2($$v^{\prime} $$, $$j^{\prime} $$) and H + D2(v = 4, j = 0) $$\to $$ D + HD($$v^{\prime} $$, $$j^{\prime} $$) reactions are presented for collision energies between $$1\,\mu {\rm{K}}$$ and $$100\,{\rm{K}}$$. The ab initio BKMP2 PES for the ground electronic state of H3 is used and all values of total angular momentum between $J=0-4$ are included. The general vector potential approach is used to include the geometric phase. The rotationally resolved, vibrationally resolved, and total reaction rate coefficients are reported as a function of collision energy. Rotationally resolved differential cross sections are also reported as a function of collision energy and scattering angle. Large geometric phase effects appear in the ultracold reaction rate coefficients which result in a significant enhancement or suppression of the rate coefficient (up to 3 orders of magnitude) relative to calculations which ignore the geometric phase. The results are interpreted using a new quantum interference mechanism which is unique to ultracold collisions. Significant effects of the geometric phase also appear in the rotationally resolved differential cross sections which lead to a very different oscillatory structure in both energy and scattering angle. Several shape resonances occur in the 1–$$10\,{\rm{K}}$$ energy range and the geometric phase is shown to significantly alter the predicted resonance spectrum. The geometric phase effects and ultracold rate coefficients depend sensitively on the nuclear spin. Furthermore, experimentalists may be able to control the reaction by the selection of a particular nuclear spin state.« less
    Cited by 1
  • Cited by 1
  • The results of accurate quantum reactive scattering calculations for the D + HD(v = 4, j = 0)more » $$\to $$ D + HD($$v^{\prime} $$, $$j^{\prime} $$), D + HD(v = 4, j = 0) $$\to $$ H + D2($$v^{\prime} $$, $$j^{\prime} $$) and H + D2(v = 4, j = 0) $$\to $$ D + HD($$v^{\prime} $$, $$j^{\prime} $$) reactions are presented for collision energies between $$1\,\mu {\rm{K}}$$ and $$100\,{\rm{K}}$$. The ab initio BKMP2 PES for the ground electronic state of H3 is used and all values of total angular momentum between $J=0-4$ are included. The general vector potential approach is used to include the geometric phase. The rotationally resolved, vibrationally resolved, and total reaction rate coefficients are reported as a function of collision energy. Rotationally resolved differential cross sections are also reported as a function of collision energy and scattering angle. Large geometric phase effects appear in the ultracold reaction rate coefficients which result in a significant enhancement or suppression of the rate coefficient (up to 3 orders of magnitude) relative to calculations which ignore the geometric phase. The results are interpreted using a new quantum interference mechanism which is unique to ultracold collisions. Significant effects of the geometric phase also appear in the rotationally resolved differential cross sections which lead to a very different oscillatory structure in both energy and scattering angle. Several shape resonances occur in the 1–$$10\,{\rm{K}}$$ energy range and the geometric phase is shown to significantly alter the predicted resonance spectrum. The geometric phase effects and ultracold rate coefficients depend sensitively on the nuclear spin. Furthermore, experimentalists may be able to control the reaction by the selection of a particular nuclear spin state.« less