Absolute triple differential cross sections (TDCS) for the ionization of molecular nitrogen by approximately=300 eV electron impact have been measured in a coplanar asymmetric arrangement. Two different values of the energy loss, Delta E=25.6 and 34 eV, have been chosen in order to investigate the ionization mechanism in an energy region where the resonant channel 3 sigma g to in sigma u, in pi u competes with the direct process. For each Delta E the TDCS have been measured at two momentum transfers, K=0.7 and 0.35 au, in order to approach the dipolar limit. Theoretical models for molecular TDCS are lacking, therefore the present results are qualitatively compared to TDCS of He obtained under analogous kinematics.

The C 1s and N 1s Auger spectra of pyrimidine, 2-chloropyrimidine, and 5-bromopyrimidine have been measured in an electron impact experiment at 1000 eV. In the case of the halogen-substituted pyrimidines, also the Cl 2p and Br 3d Auger spectra have been recorded. We have thoroughly analyzed and interpreted all the Auger spectra recorded here with the aid of accurate Green's function calculations with a large basis set. The spectra are extremely complex with thousands of states contributing and almost no single-state feature even near the double ionization threshold. Besides reproducing and explaining with great detail nearly all the main spectral features observed, the calculations have successfully unraveled the interplay among the different C 1s core hole chemical shifts in each molecule and how this affects some fingerprinting details in the composite C 1s Auger spectra.

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The results of an experimental and theoretical study of the ionization and ionization–excitation of Mg by electron impact at 400 eV and two values of the momentum transfer are presented. The measurements were performed using the (e, 2e) technique in coplanar asymmetric kinematics. The experimental data are compared with predictions from first-order and second-order hybrid distorted-wave + R matrix approaches. While good agreement between theory and experiment is seen for the angular dependence of the cross sections, serious discrepancies remain for the relative intensities of the satellite lines.