unit cell and scattering region

[sac_harode]

i want to calculate:
1) the number of unit cell in CrO2 electrode.
2) scattering region in CrO2-MgO barrier.
what is procedure to find these things ??

[Petr Khomyakov]

The number of unit cells in an electrode structure is the total number of atoms in the electrode divided by the number of atoms in the unit cell. It then depends on how you have defined the unit cell and electrode structure for CrO2.

It is not clear what exactly you mean by "to calculate the scattering region". You may have a look at the following tutorial, http://docs.quantumwise.com/tutorials/atk_transport_calculations.html?highlight=transport, to get an idea of how the scattering problem is formulated and solved in relation to the electron transport problem that I guess you are interested in.