Electron-energy-loss-based spectroscopies: A molecular viewpoint

A review is given of electron-energy-loss molecular spectroscopies with emphasis on recent studies of core excitation of free molecules by inner-shell electron-energy-loss spectroscopy (ISEELS). Issues discussed include: resolution capabilities, momentum transfer dependence, dipole oscillator strength determination, extended fine structure and bond length determination. Coincidence techniques between inelastically scattered electrons and electrons or ions produced in the decay of electronic excited states are also reviewed.