skip to main content

Title: Accuracy of the centrifugal sudden approximation in the H + CHD{sub 3} → H{sub 2} + CD{sub 3} reaction

The initial state selected time-dependent wave packet method has been extended to calculate the coupled-channel reaction probabilities with total angular momentum J{sub tot} > 0 for the title reaction with seven degrees of freedom included. Fully converged integral cross sections were obtained for the ground and a number of vibrational excited initial states on a new potential energy surface recently constructed by this group using neural network fitting. As found from a previous study with the centrifugal sudden (CS) approximation, all these initial vibrational excitations investigated in this study enhance the reactivity considerably at a given collision energy, in particular the CH stretch excited state. The energy initially deposited in CH stretch motion is more effective than translational energy on promoting the reaction in the entire energy region, while for CH bending or CD{sub 3} umbrella excitations only at the high collision energy the vibrational energy becomes more effective. Our calculations also revealed that the accuracy of the CS approximation considerably deteriorates with the increase of J{sub tot}, in particular on the threshold energy. The CS approximation underestimates the integral cross sections for all these initial states, albeit not very severely. In general, it works better at high collision energiesmore » and for vibrationally excited initial states, with the increase of integral cross section.« less
Authors:
; ; ;  [1]
  1. State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)
Publication Date:
OSTI Identifier:
22420134
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ACCURACY; ANGULAR MOMENTUM; COLLISIONS; DEGREES OF FREEDOM; DEPOSITS; EXCITATION; EXCITED STATES; INTEGRAL CROSS SECTIONS; NEURAL NETWORKS; POTENTIAL ENERGY; PROBABILITY; REACTIVITY; SUDDEN APPROXIMATION; THRESHOLD ENERGY