  A new model CRAC:EPII (Cosmic Ray Atmospheric Cascade: Electron Precipitation
Induced Ionization) is presented. The CRAC:EPII is based on Monte Carlo
simulation of precipitating electrons propagation and interaction with matter
in the Earth atmosphere. It explicitly considers energy deposit: ionization,
pair production, Compton scattering, generation of Bremsstrahlung high energy
photons, photo-ionization and annihilation of positrons, multiple scattering as
physical processes accordingly. The propagation of precipitating electrons and
their interactions with atmospheric molecules is carried out with the GEANT4
simulation tool PLANETOCOSMICS code using NRLMSISE 00 atmospheric model. The
ionization yields is compared with an analytical parametrization for various
energies of incident precipitating electron, using a flux of mono-energetic
particles. A good agreement between the two models is achieved. Subsequently,
on the basis of balloon-born measured spectra of precipitating electrons at
30.10.2002 and 07.01.2004, the ion production rate in the middle and upper
atmosphere is estimated using the CRAC:EPII model
