Title: ENERGY STATES IN SUPERLATTICES CONNECTED WITH INCOMMENSURATE PHASE PRESENCE
Author(s): D.M.Bercha (Institute of Solid State Physics and Chemistry, Uzhgorod National University 54~Voloshina~Str., 88000 Uzhgorod, Ukraine; Institute of Physics, Pedagogical University, 16a Rejtana Str., 35-310 Rzesz\'ow, Poland), K.E.Glukhov (Institute of Solid State Physics and Chemistry, Uzhgorod National University 54~Voloshina~Str., 88000 Uzhgorod, Ukraine; E-mail: glukhov@mail.uzhgorod.ua), L.Yu.Kharkhalis (Institute of Solid State Physics and Chemistry, Uzhgorod National University 54~Voloshina~Str., 88000 Uzhgorod, Ukraine)

The electron behavior in incommensurate phase in Sn$_2$P$_2$Se$_6$ has been considered as the motion in the Mathieu potential. A simple model of effective potential change under a transition incommensurate -- domain-like structure has been proposed. A behavior of the obtained localized levels system versus the model parameters has been investigated.

Key words: modulated structures, Mathieu crystal, incommensurate, ferroelectrics
PACS:64.70.Rh