Mutual Capture of Dipolar Molecules at Low and Very Low Energies. I. Approximate Analytical Treatment

Abstract

Approximate analytical expressions are derived for the low-energy rate coefficients of capture of two identical dipolar polarizable rigid rotors in their lowest nonresonant (j(1) = 0 and j(2) = 0) and resonant (j(1) = 0,1 and j(2) = 1,0) states. The considered range extends from the quantum, ultralow energy regime, characterized by s-wave capture, to the classical regime described within fly wheel and adiabatic channel approaches, respectively. This is illustrated by the table of contents graphic (available on the Web) that shows the scaled rate coefficients for the mutual capture of rotors in the resonant state versus the reduced wave vector between the Bethe zero-energy (left arrows) and classical high-energy (right arrow) limits for different ratios δ of the dipole-dipole to dispersion interaction.

Electronic nonadiabatic effects in low temperature radical-radical reactions. I. C(3P) + OH(2Π)

“…This nonadiabaticity mainly is responsible for the fact that our calculated capture rate constants at the considered temperatures (up to 200 K) markedly exceed the results obtained by CT calculations on the single electronic ground state PES corrected by the statistical electronic factor f el (T) (Ref. 16). The maximum of the rate constant in our results is shifted from about 7 (Ref.…”

“…[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. For example, one determines numbers of open channels W(E,l) (i.e., numbers of ACs for which E > E 0,i (l)) or activated complex partition functions Q * defined by…”

“…14 On the other hand, quantum models are required for ultralow temperature applications. [15][16][17][18] One should note that the AC concept can be exploited in a variety of ways. Besides capture rate constants also capture cross sections in scattering theory have been expressed in terms of numbers of open ACs, see, e.g., Refs.…”

Adiabatic channel capture theory applied to cold atom–molecule reactions: Li + CaH $\to $ LiH + Ca at 1K

“…The close similarity in the behavior of the probabilities for L = 10 and 20 is consistent with previous theoretical work, which recommended using general analytical fitting functions for capture probabilities for the polarization (R −4 ) and dispersion (R −6 ) potentials (see, e.g., Refs. [59][60][61]). The insets also show the WKB-corrected classical probabilities, which provide an upper bound for both the classical and quantum results.…”

Quantum effects in the capture of charged particles by dipolar polarizable symmetric top molecules. II. Interplay between electrostatic and gyroscopic interactions

“…2-4. An extension of this treatment to very low collision energies, where a small number of partial waves contribute to the capture, was done for anisotropic charge-induced dipole interaction, 5 resonance dipole-dipole interaction, 6,7 and charge-quadrupole interaction. 8 In all these cases, the energy-dependent capture rate coefficient approaches a constant value at zero-energy, i.e., it conforms with the Bethe law.…”