To build these multilayers TiO2 (001) / ZnO (101) / TiO2 (001) in castep, you must obtain a (001) surface of TiO2 and (101) surface of ZnO, according to the following steps:

The first step:

1. Import TiO2.

2. Build → cleave surface.

3. Select a cleave plane (hkl), which is (001).

4. Select the thickness of the surface.

and repeat the previous points (from1 to 4) to ZnO (101), now you have the required surface, to build the above multilayers go to the second step which is:

1. Build → Build layers.

2. Chose the layer 1, TiO2 (001).

3. Chose the layer 2, ZnO (101).

2. Chose the layer 3, TiO2 (001).

Then you must decide if you want, a crystal or layer.

But, you must consider in mind that there is an important condition must be available in any multilayer which is: the lattice mismatch between TiO2 (001) and ZnO (101) is smaller than 5%. If this percent more than 5%, this is mean this multilayer is not stable.

thank you Mr Hamad R. Jappor

I recommended Hamad R. Jappor answer, but I think must be added the vacuum slsb

I agree with Moaid k Hussain

I agree with Moaid k Hussain

Moaid K Hussain Vacuum can be added once the layer is formed by the following steps.

1. Build → Build layers.

2. Chose the layer 1, TiO2 (001).

3. Chose the layer 2, ZnO (101).

4. Chose the layer 3, TiO2 (001).

then choose the layers as surfaces

then you can add Vacuum.

No need to add vacuum separately during building the surfaces.