Shape resonances in the photoionization of N 2 0

We repo~ th~ results of studies of the cross sections and photoelectron asymmetry parameters for phot.otomzatlOn ~f the 7 0' level of N 20 using Hartree-Fock photoelectron continuum orbitals. These s~udt~ were ~O~lVa~ed by recent measurements which showed significant non-Franck-Condon vtbrattonal dtstnbutwns at low ph?toel~tron energies where previously only autoionizing resonances, but no shape resonance, had been Identified. Our results establish that there are two u shape resonances i? the 7u ionizati?n ~ontinu~m, a pronounced resonance at low photoelectron energies, and another at htgher energy whtch ts essentially obscured in the vibrationally unresolved cross sections. The sh~pe resonant st~cture t~at ~merges from these studies differs significantly from the predictions of previous model studies. Studies 10 progress reveal a rich and unusual dependence of these resonances on changes in internuclear distances.