What is the stacking sequence for the 6H-SiC polymorph of SiC?

[Richie9384]

I'm having difficulty understanding polymorphs and stacking. I'm doing simulations on 6H-SiC but I think I may have the wrong structure..

I don't understand the stacking sequence, the picture I attached shows the stacking sequence for 6H-SiC, but I can't make any sense out of it. The arrangement of the A's do not look similar, although B and C seem consistent in terms of the arrangement of atoms.

Basically I've just tried to assemble the unit cell by arranging the atoms in the way shown, the unit cell I used as 12 atoms, I attached a similar picture from the web of the unit cell.

 

[BigJDubs]

Polymorphs are different crystalline structures of the same compound. In the case of SiC, there are two polymorphs, 3C and 6H. The way they are organized in the lattice is determined by their stacking sequence. The 6H polymorph has a hexagonal structure, in which the atoms are arranged in layers of three adjacent atoms. These layers are stacked together in an ABCABC pattern. This means that the first layer of atoms will be A, then B, followed by C, and so on.In terms of your simulation work, it is important to ensure that you have the correct structure of the material before running any simulations. This means that you will need to check the stacking sequence for the material you are simulating and make sure that it is correct. As for the unit cell, the structure of 6H-SiC should have 12 atoms per unit cell, arranged in the ABCABC pattern. I hope this helps!