Validity of the Born-Oppenheimer approximation in the indirect-dissociative-recombination process

0498445 - ÚFCH JH 2019 RIV US eng J - Článek v odborném periodiku
Čurík, Roman - Hvizdoš, Dávid - Greene, C. H.
Validity of the Born-Oppenheimer approximation in the indirect-dissociative-recombination process.
Physical Review A. Roč. 98, DEC 2018 (2018), č. článku 062706. ISSN 2469-9926. E-ISSN 2469-9934
Grant CEP: GA ČR(CZ) GA18-02098S
Institucionální podpora: RVO:61388955
Klíčová slova: Approximation theory * Degrees of freedom (mechanics) * Born-Oppenheimer approximation
Obor OECD: Physical chemistry
Impakt faktor: 2.907, rok: 2018

An alternative method is introduced to solve a simple two-dimensional model describing vibrational excitation and dissociation processes during the electron-molecule collisions. The model works with one electronic and one nuclear degree of freedom. The two-dimensional R matrix can be constructed simultaneously on the electronic and nuclear surfaces using all three forms developed previously for electron-atom and electron-molecule collisions. These are the eigenchannel R-matrix form, inversion technique of Nesbet and Robicheaux, and the Wigner-Eisenbud-type form using expansion over the poles of the symmetrized Hamiltonian. The 2D R-matrix method is employed to solve a simple model tailored to describe the dissociative recombination and the vibrational excitation of H2+ cation in the singlet ungerade symmetry 1Σu. These results then serve as a (near-exact) benchmark for the following calculation in which the R-matrix states are replaced by their Born-Oppenheimer approximations. The accuracy of this approach and its correction with the first-order nonadiabatic couplings are discussed.
Trvalý link: http://hdl.handle.net/11104/0290811