Creating a supercell from unit cell

[hsuya]

Can I optimize a unit cell and then use the same as a supercell? Would it be  a valid approach. I am thinking of creating a 4x4x1 MoS2 supercell by optimizing a unit cell.

[mlee]

I would like to recommend the relaxation of the supercell after optimization of unitcell. It will be easier to converge the criteria. And it depends on  how accuracy you need.

[Petr Khomyakov]

Can I optimize a unit cell and then use the same as a supercell? Would it be  a valid approach.

That is a common approach to optimize a pristine system using a minimal cell. If your supercell derived from this optimized  unit cell is interfaced to something or there are adsorbents on the MoS2 surface, then you may definitely want to do additional geometry optimization of the entire or part of the supercell structure, as suggested in a previous post..

[hsuya]

Can you help me with the "relaxing of structure"? What does it mean and how to do it?

[Petr Khomyakov]

Please read the manual page https://docs.quantumatk.com/manual/Types/OptimizeGeometry/OptimizeGeometry.html and the tutorial https://docs.quantumatk.com/tutorials/geometry_optimization/geometry_optimization.html.