Spin-orbit transitions in the N+(3P JA)+H2 → NH+(X2Π, 4Σ-) + H(2S) reaction, using adiabatic and mixed quantum-adiabatic statistical approaches

[EN]The cross section and rate constants for the title reaction are calculated for all the spin–orbit states of using two statistical approaches, one purely adiabatic and the other one mixing quantum capture for the entrance channel and adiabatic treatment for the products channel. This is made by u...

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Detalles Bibliográficos
Autores: Gómez Carrasco, Susana Raquel, Félix González, Daniel, Aguado, Alfredo, Roncero, Octavio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Universidad de Salamanca (USAL)
Repositorio:GREDOS. Repositorio Institucional de la Universidad de Salamanca
OAI Identifier:oai:gredos.usal.es:10366/169524
Acceso en línea:http://hdl.handle.net/10366/169524
Access Level:acceso abierto
Palabra clave:Ab-initio methods
Potential energy surfaces
Spin-orbit interactions
Statistical models
Numerical methods
Propagation matrix
Reaction rate constants
Complete-active space self-consistent field
Descripción
Sumario:[EN]The cross section and rate constants for the title reaction are calculated for all the spin–orbit states of using two statistical approaches, one purely adiabatic and the other one mixing quantum capture for the entrance channel and adiabatic treatment for the products channel. This is made by using a symmetry adapted basis set combining electronic (spin and orbital) and nuclear angular momenta in the reactants channel. To this aim, accurate ab initio calculations are performed separately for reactants and products. In the reactants channel, the three lowest electronic states (without spin–orbit couplings) have been diabatized, and the spin–orbit couplings have been introduced through a model localizing the spin–orbit interactions in the N+ atom, which yields accurate results as compared to ab initio calculations, including spin–orbit couplings. For the products, 11 purely adiabatic spin–orbit states have been determined with ab initio calculations. The reactive rate constants thus obtained are in very good agreement with the available experimental data for several ortho-H2 fractions, assuming a thermal initial distribution of spin–orbit states. The rate constants for selected spin–orbit JA states are obtained, to provide a proper validation of the spin–orbit effects to obtain the experimental rate constants.