Both oxides have several polymorphs. If you need the corundum structure, then M is at [0; 0; 0.3522] and O at [0.3063; 0; 0.25]. You can find other possible structures at http://www.crystallography.net/

Thank you!

Please use the terms correctly: Fe2O3 is a structure, and since Fe and Al are different atomes the coordinates are perhaps not identical (but this also happens for different Fe2O3 description :-)). Again: main message: Don't mix lattices with structure. Only because all around you do it it doesn't mean it is correct. :-)

Sure we know the difference between lattice and structure.

Of course you do, but why do you use it then in the wrong way? Here are many readers who do not diistinguish between both terms and don't see any difference.