skip to main content

Title: Geometric phase effects in the ultracold H + H2 reaction

The H3 system has served as a prototype for geometric phase (GP) effects in bimolecular chemical reactions for over three decades. Despite a large number of theoretical and experimental efforts, no conclusive evidence of GP effects in the integral cross section or reaction rate has been presented until recently. Here we report a more detailed account of GP effects in the H + H2(v = 4, j = 0) → H + H2(v', j') (para-para) reaction rate coefficients for temperatures between 1 μK (8.6 × 10–11 eV) and 100 K (8.6 × 10–3 eV). The GP effect is found to persist in both vibrationally resolved and total rate coefficients for collision energies up to about 10 K. The GP effect also appears in rotationally resolved differential cross sections leading to a very different oscillatory structure in both energy and scattering angle. It is shown to suppress a prominent shape resonance near 1 K and enhance a shape resonance near 8 K, providing new experimentally verifiable signatures of the GP effect in the fundamental hydrogen exchange reaction. As a result, the GP effect in the D + D2 and T + T2 reactions is also examined in the ultracold limit andmore » its sensitivity to the potential energy surface is explored.« less
Authors:
ORCiD logo [1] ;  [2] ; ORCiD logo [2]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Univ. of Nevada, Las Vegas, NV (United States)
Publication Date:
OSTI Identifier:
1330279
Report Number(s):
LA-UR-16-25624
Journal ID: ISSN 0021-9606; TRN: US1701322
Grant/Contract Number:
AC52-06NA25396; 20140309ER
Type:
Published Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 145; Journal Issue: 16; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Laboratory Directed Research and Development (LDRD) Program
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; astronomy and astrophysics; inorganic and physical chemistry; ultracold chemistry; hydrogen reaction