A B C
A': 1 1 0
B': -1 1 0
C' 0 0 1Yes, it is caused by different version. In the ATK12.8.2, several parameters should be adjusted because the two primitive unit vectors in xy planes of hexagonal MoS2 are taken along the lines with an angle of +/-60 degree with respect to the X axis.
In the supercell conversion from a hexagonal primitive unit cell to an orthorhombic supercell:
A B C
A': 1 1 0
B': 1 -1 0
C' 0 0 1
In the step of repeating orthorhombic supercell, the repetition number is chosen along at the A direction with "A=20".
Additional step is needed: "Swap Axes". You may try the options in both the "swap the unit cell axes" and "swap the coordinate system axes" so that the lattice parameters is the same with those shown in the video.
Thanks for raising the issue, and thanks ZH for providing the details. To be slightly more correct, the transformation is better made asCodeA B C
A': 1 1 0
B': -1 1 0
C' 0 0 1
to avoid making a left-handed cell.
We'll look into fixing the tutorial to clarify things.
It can be noted that the "A'=2A+B" version also gives an orthorhomic cell, just not aligned along the xyz axes. Another way to align the cell is therefore to use the original transformation and then go to Lattice Parameters and select "SimpleOrthorhomic" as the lattice (with "Keep Fractional coordinates"). Also, whether or not to repeat along A or B, and how to swap the axes, depends on whether you are making an armchair or zigzag tube.