Analytical Formula for the Electron Inelastic Mean Free Path

The electron inelastic mean free path (IMFP) is the average distance between successive inelastic collisions of an electron moving in a medium with a given energy. Within the dielectric formalism, the IMFP is defined by an integral. The problem is that the integration is rather complicated. In 2015, an analytical formula for IMFPs was derived from this definition ( J. Phys. Chem. C 2015, 119, 23627–23631). However, the derived formula is restricted to energies above 500 eV. This limitation is overcome in this work. The lower limit of the present analytical formula for IMFPs is about 50 eV.