QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: hsuya on November 11, 2019, 05:44

Title: Creating a supercell from unit cell
Post by: hsuya on November 11, 2019, 05:44

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.

Title: Re: Creating a supercell from unit cell
Post by: mlee on November 11, 2019, 09:09

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.

Title: Re: Creating a supercell from unit cell
Post by: Petr Khomyakov on November 11, 2019, 09:14

Quote from: hsuya on November 11, 2019, 05:44

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..

Title: Re: Creating a supercell from unit cell
Post by: hsuya on November 13, 2019, 06:18

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

Title: Re: Creating a supercell from unit cell
Post by: Petr Khomyakov on November 13, 2019, 15:16

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.