The periodic models of aperiodic systems were described. For the point defects super-cell and cyclic cluster models were compared for the O vacancy in corundum Al2O3. The single and repeated slab models of (001) surface of MgO crystal were compared by using the results of LCAO Hartree-Fock and DFT calculations.

Trends in Calculation of Point and Extended Defects in Wide-Gap Solids - Periodic Models of Aperiodic Systems. R.A.Evarestov: Physica Status Solidi A, 2005, 202[2], 235-42