The pseudopotential model is used for the evaluation of the core level ioni
sation intensities (by the electron impact). The central atom effective pha
se shift is calculated for K EELFS spectra in this framework. The Si K EELF
S spectra were calculated and compared with the experimental data. The comp
arison of experimental and calculated results is performed on the base of t
he electron dispersion law which takes into account electron-plasmon intera
ction.