Schematic profile of the geometry and energetics of the channels for reactants and products, and for the transition state for the reaction giving or . In the collision energy range considered, HD is in its vibrational state. It is shown that vibrational states for HF up to and for HD up to can be populated. The large ellipse shows the entrance channel van der Waals well and the transition state features for the present potential energy surface, PES III. The exit channel van der Waals well occurs in a collinear configuration with a depth similar to that of the entrance channel.
Calculated cross sections for PES III for rotationally selected initial state (, 1, 2, and 3) as a function of collision energy.
Isotopic branching ratios for PES III (solid lines) and SW PES (dashed lines) for rotationally selected initial state (, 1, 2, and 3) as a function of collision energy.
Integral cross sections calculated in comparison with the experimental results of Ref. 6 (full and open dots for the HF and DF channels). They are obtained by taking contributions of the state selected cross section of Fig. 2 from and , which are experimentally given as 82% and 18%, respectively. Experiments do not provide absolute values, but only relative ones so a normalization is required for comparison. Those for the two PES differ slightly (less than 5%). Our results for the SW surface agree with those of Ref. 6 within a few percent. The present calculations extend the energy range beyond .
Cross sections for production of HF (, 2, and 3: upper panel) and DF (, 2, 3, and 4: lower panel) in specific vibrational states. Symbols: experiments (Ref. 35); curves: present calculations (PES III). , open triangles and dots; , full squares and dashes; , full dots and continuous curves; , full triangles and dashed-dot curves; , diamonds and double-dash-dot curves.
Arrhenius plot (logarithm of rate constants vs inverse temperature) for the reaction. Dots: experimental data from Persky (2005) (Ref. 22); full lines: PES III (present calculations); dashed lines: SW (present calculations). Upper panel: the channel; lower panel: the channel.
Numerical parameters for the production runs of the hyperquantization algorithm.
Comparison between experimental and theoretical rate constants (in ) for the reaction as a function of temperature.
Comparison between theoretical rate constants for SW and PES III (in ) for the reaction as a function of temperature.
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