Shape Resonances in Atom and Molecule Scattering

The 2P shape resonance in e-Be scattering has served as the test case for almost all the theoretical approaches to the treatment of electron scattering resonances and the earliest applications of the dilated electron propagator have also focused on this system /21,26,40/. Theta trajectories from different decouplings of the bi-orthogonal dilated electron propagator are displayed in fig. 4. The optimal value of a = 0.75 has been determined through a separate a-trajectory /26/. 

The Siegert orbital approach to the electron propagator has not been effective in the treatment of the e-Be 2P shape resonance. Both our bi-orthogonal 

Static Exchange plus Polarizability /85/ Phase Shift 0.20 0.28 

Static Exchange plus Polarizability /86/ Cross Section 0.16 0.14 

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