skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Effects of reactant rotational excitations on H 2 + NH 2 → H + NH 3 reactivity

Publication Date:
Sponsoring Org.:
OSTI Identifier:
Grant/Contract Number:
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 141; Journal Issue: 24; Related Information: CHORUS Timestamp: 2016-12-28 17:05:45; Journal ID: ISSN 0021-9606
American Institute of Physics
Country of Publication:
United States

Citation Formats

Song, Hongwei, and Guo, Hua. Effects of reactant rotational excitations on H 2 + NH 2 → H + NH 3 reactivity. United States: N. p., 2014. Web. doi:10.1063/1.4904483.
Song, Hongwei, & Guo, Hua. Effects of reactant rotational excitations on H 2 + NH 2 → H + NH 3 reactivity. United States. doi:10.1063/1.4904483.
Song, Hongwei, and Guo, Hua. 2014. "Effects of reactant rotational excitations on H 2 + NH 2 → H + NH 3 reactivity". United States. doi:10.1063/1.4904483.
title = {Effects of reactant rotational excitations on H 2 + NH 2 → H + NH 3 reactivity},
author = {Song, Hongwei and Guo, Hua},
abstractNote = {},
doi = {10.1063/1.4904483},
journal = {Journal of Chemical Physics},
number = 24,
volume = 141,
place = {United States},
year = 2014,
month =

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.4904483

Citation Metrics:
Cited by: 9works
Citation information provided by
Web of Science

Save / Share:
  • Rotational mode specificity of the title reaction is examined using an initial state selected time-dependent wave packet method on an accurate ab initio based global potential energy surface. This penta-atomic reaction presents an ideal system to test several dynamical approximations, which might be useful for future quantum dynamics studies of polyatomic reactions, particularly with rotationally excited reactants. The first approximation involves a seven-dimensional (7D) model in which the two non-reactive N–H bonds are fixed at their equilibrium geometry. The second is the centrifugal sudden (CS) approximation within the 7D model. Finally, the J-shifting (JS) model is tested, again with themore » fixed N–H bonds. The spectator-bond approximation works very well in the energy range studied, while the centrifugal sudden and J-shifting integral cross sections (ICSs) agree satisfactorily with the coupled-channel counterparts in the low collision energy range, but deviate at the high energies. The calculated integral cross sections indicate that the rotational excitation of H{sub 2} somewhat inhibits the reaction while the rotational excitations of NH{sub 2} have little effect. These findings are compared with the predictions of the sudden vector projection model. Finally, a simple model is proposed to predict rotational mode specificity using K-averaged reaction probabilities.« less
  • Excitation of reactant rotational degrees of freedom is known to influence reactivity in bimolecular reactions. In this work, this effect is examined for several prototypical activated atom-diatom and atom-triatom reactions through exact quantum scattering calculations on accurate ab initio potential energy surfaces. To rationalize these mode-specific effects, the recently proposed sudden vector overlap model is extended to include rotational motions of reactants. Specifically, the enhancement of reactivity is attributed to their coupling with the reaction coordinate at the transition state, as quantified by the alignment between the corresponding normal mode vectors. In addition, a Franck-Condon model is introduced to predictmore » the effect of reactant rotational excitation for reactions in which the reactant rotations are decoupled from the reaction coordinate.« less
  • We have investigated the direct reaction of Na{sup *}(4 {sup 2}{ital P}) with H{sub 2} to form the product NaH. Using far-wing absorption techniques, we have measured absorption into the NaH{sub 2} collision complex, followed by branching into nonreactive (formation of Na{sup *}) or reactive (formation of NaH({ital X} {sup 1}{Sigma}{sup +}({ital v}{prime}{prime},{ital J}{prime}{prime}))) channels. We have observed the reaction to occur both via the attractive potential-energy surfaces and over a barrier on the repulsive surfaces. We have studied the effect of reactant orbital alignment on product rotational distribution for {ital v}{prime}{prime}=1. Specifically we find reaction on the repulsive surfacesmore » leads preferentially to low rotational product states of NaH, while reaction on the attractive surfaces leads preferentially to high rotational states.« less
  • We investigate the pairing correlations in neutron-rich Mg and Cr isotopes by paying special attention to the roles of continuum states and neutron skins. By performing the coordinate space Hartree-Fock-Bogoliubov calculation with the density-dependent contact pairing force, we show that the predicted pairing properties strongly depend on not only isoscalar but also isovector density dependence of the pairing force. We propose that the moment of inertia of the low-lying rotational excitations can provide desirable information to construct a reliable pairing density functional for exploring the novelty of the pairing correlations in neutron-rich nuclei close to the drip line.
  • A simple classical model was proposed to study the effect of reactant rotation on reactivity for atom-diatom collisions. The model was able to reproduce trends recently reported in the reaction cross section for H + H/sub 2/ and other systems. Stretching of the target diatom bond during the collision was found to enhance the effectiveness of rotation in promoting reaction. This suggested that rotation may promote reaction more readily on surfaces with late barriers. The model results were found to be particularly sensitive to the long-range anisotropy of the potential, implying that rotational excitation of reactants may be a meansmore » of probing that part of the potential.« less