This type of structure is represented by TiO2 and other example are includes MnO2 , SnO2 , MgF2, NiF2 etc
In Rutile structure:
O-2 = ions forms hexagonal cubic
packing (HCP).
M+4 =Tetravalent cations are occupied 50 % (1/2) of octahedral voids (OV) while all the tetrahedral voids (TO) are empty.
HCP= Lattice points (LP) = O-2=
6
M+4 ions
= OV (50%) =6 x 1/2 = 3
M3O6
= MO2
It means
each HCP unit cell certain three (M+4 ) and six (O-2 )ions
ABQ3 is a proto type solid where A is
a divalent
cation and B is a tetravalent cation.
A+2 = Divalent cations
B+4 =Tetravalent cations
In Pervoskite structure:
A+2 = placed at corner of cubic unit cell
O-2 = placed at all the face centre
That
means A+2 and O-2 ions combinelly form CCP/FCC
like structure and
B+4 = Tetravalent cations occupy the central octahedral voids (25% of
total OV) i.e centre of the centre of the unit cell so general formula is ABO3
Other
examples are BaTiO3, SrTiO3
