Inner-shell excitation of molecules by electron impact

The author reviews recent developments in ways of exciting inner shells. Developments in electron energy loss spectroscopy (EELS) and its use in understanding the strikingly non-atomic gross features of molecular inner-shell absorption spectra are also included. It is suggested that the energy-loss technique combined with ion-mass separation is at present one of the major sources of knowledge of the ionic decay and fragmentation of core-hole molecules. The method of detecting electron-molecule resonances in high-resolution excitation functions, has now been extended to the inner-shell regions; this has led to the observation of core-excited negative-ion states. (Auth.)