Foreign imaging in Auger spectroscopy: The Si 2pspectrum of silicon tetrafluoride

We performed Green's function calculations on the double ionization of SiF₄ in order to interpret its Si 2p Auger spectrum, which has caused controversy for a decade. We provide an accurate interpretation and a model of far wider generality in the Auger study of ionic species. Contrary to the usual self-imaging picture of Auger spectroscopy, the silicon spectrum exhibits eight distinct bands reflecting a complete and precise image of the fluorine ligands, due to strong hole-localization effects. The generality of this foreign-imaging character of Auger spectroscopy is discussed.