Formation of Na-containing complex molecules in the gas phase in dense molecular clouds: quantum study of the Na+ + H2 and Na+ + D2 radiative association step

Abstract

The Na + H 2 radiative association (RA) is the first and limiting step in the models of formation of NaH in the gas phase. Also the accurate evaluation of the RA rate is required to be included in chemical models of dense molecular clouds. In this work a quantum study of the formation of the Na + H 2 and Na + D 2 complexes by radiative association is presented. We use a 3D potential energy surface published recently and a quantum dynamical method based on the driven equation formalism. The values obtained for the radiative association rates are compared with previous evaluations based on approximate methods and the possible role played by these two processes in the gas phase chemistry of dense molecular clouds is discussed.

Predissociation spectra of the 35Cl−(H2) complex and its isotopologue 35Cl−(D2)

“…We take the dipole moment to lie along the intermolecular vector -R and to be proportional to R. This approximation has proved to be quite accurate in our previous studied dedicated to other atomic ion-diatom complexes like H À (N 2 ), 6 H À (CO) 15 or Na + (H 2 ). 16 In the present case, this approximation is furthermore supported by the results obtained by Buchachenko et al 3 The interested reader can find in any of these previous studies the expression of the dipole moment matrix elements from which result the selection rules: Dp = 0, DJ = 0, AE1, Dj = 0, Dl = AE1.…”

Complexes of Alkali Metal Cations and Molecular Hydrogen: Potential Energy Surfaces and Bound States

“…1,2 In addition, in the study of the interstellar medium there is interest in processes involving ubiquitous H 2 molecules and relatively abundant metallic cations. [3][4][5] Another motivation for studying these systems is their application in processes of reversible storage of hydrogen in porous materials, [6][7][8][9][10] where dopant metal cations act as centers to which hydrogen molecules attach and isotopic substitution effects (D 2 by H 2 ) have been found to be relevant. 11 In all these cases, it is also interesting to study the differences in the interaction depending on whether the molecule is in the ground rotational state (para-H 2 , ortho-D 2 ) or in the first rotationally excited state (ortho-H 2 , para-D 2 ), as has been found in related works.…”

Classical Wigner model based on a Feynman path integral open polymer

“…The calculation of reaction rate constants for other radiative association reactions and the development of the methods to conduct these calculations has continued in the research group, and among collaborators, of the author since the publication of paper I. [106][107][108][109][110][111][112][113][114] One of the main directions that further research is going toward is the calculation of radiative association rate constants for systems larger than diatoms. As radiative association generally becomes more likely the larger the molecule, due to a more long lived activated complex, as explained e.g.…”