Abstract
Our interest lies in investigating nuclear dynamics of diatomic molecules in resonant collisions with electrons. This work specifically aims at calculating the cross sections for vibrational excitation of O2 by an electron impact via the 2Πg resonance.
The process starts with obtaining the potential energy curves of O2 and its negative ion. This was done by standard ab-initio quantum chemistry methods (CASSCF, MRCI - implemented in Molpro package [1]) under different conditions.
Quality of the resulting curves was controlled by comparing calculated electron affinities with experimental values. In our earlier work we used the R-matrix method (within UKRmol codes [2]) to obtain eigenphase sums and resonant energy and widths.
Nuclear dynamics was then solved using the local complex potential approximation [3], but it proved insufficient, as it failed to reproduce the cross sections energy dependence properly. In the presented results we used a numerically solvable two-dimensional scattering model [4] to produce the eigenphase sums, which then served as the basis for building of the nonlocal resonance model [5].
Resulting cross sections were compared to experimental data [6]. [1] H.-J. Werner, P.
J. Knowles, G.
Knizia and others, see http://www.molpro.net [2] J. M.
Carr, P. G.
Galiatsatos, J. D.
Gorfinkiel and others, Eur. Phys.
J. D 66 (2012) [3] L.
Dube, A. Herzenberg, Phys.
Rev. A 20, 194 (1979) [4] K.
Houfek, T. N.
Rescigno and C. W.
McCurdy Phys. Rev.
A 73, 032721 (2006) [5] W. Domcke, Phys.
Rep. 208, 97 (1991) [6] M. Allan, J.
Phys. B 28, 5163 (1995)