  The phenomenon of the spontaneous electric polarization (ferro- and
antiferroelectricity) is one of the fundamental problems of the solid-state
physics. Although, there has been lot of experimental and theoretical progress,
still needs to be made to understand the origine of the spontaneous electric
polarization. A new microscopic theory that is based on the perfectly elastic
electron-atom and atom-atom collisions, crystal structure and the chemical
composition of the compounds is developed to calculate the critical
temperatures for materials with spontaneous electric polarization. The
reliability of this model was examined by comparing the experimental results
with calculated values.
