Back to Search
Start Over
Non-adiabatic couplings and dynamics in proton transfer reactions of Hn (+) systems: Application to H2+H2 (+)→H+H3 (+) collisions.
- Source :
-
The Journal of chemical physics [J Chem Phys] 2015 Dec 21; Vol. 143 (23), pp. 234303. - Publication Year :
- 2015
-
Abstract
- Analytical derivatives and non-adiabatic coupling matrix elements are derived for Hn (+) systems (n = 3-5). The method uses a generalized Hellmann-Feynman theorem applied to a multi-state description based on diatomics-in-molecules (for H3 (+)) or triatomics-in-molecules (for H4 (+) and H5 (+)) formalisms, corrected with a permutationally invariant many-body term to get high accuracy. The analytical non-adiabatic coupling matrix elements are compared with ab initio calculations performed at multi-reference configuration interaction level. These magnitudes are used to calculate H2(v(')=0,j(')=0)+H2 (+)(v,j=0) collisions, to determine the effect of electronic transitions using a molecular dynamics method with electronic transitions. Cross sections for several initial vibrational states of H2 (+) are calculated and compared with the available experimental data, yielding an excellent agreement. The effect of vibrational excitation of H2 (+) reactant and its relation with non-adiabatic processes are discussed. Also, the behavior at low collisional energies, in the 1 meV-0.1 eV interval, of interest in astrophysical environments, is discussed in terms of the long range behaviour of the interaction potential which is properly described within the triatomics-in-molecules formalism.
Details
- Language :
- English
- ISSN :
- 1089-7690
- Volume :
- 143
- Issue :
- 23
- Database :
- MEDLINE
- Journal :
- The Journal of chemical physics
- Publication Type :
- Academic Journal
- Accession number :
- 26696058
- Full Text :
- https://doi.org/10.1063/1.4937138