QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: hsuya on July 2, 2020, 04:58

Title: Change in space group
Post by: hsuya on July 2, 2020, 04:58

I want to create an MoS2 monolayer (4x4x1) supercell but when I delete the extra layer after adding molybdenite the space group changes from p63/mmc to p6m2. I want to retain the p63/mmc space group. How can I do that?

Title: Re: Change in space group
Post by: Daniele Stradi on July 3, 2020, 17:49

Hello,

the Schoenflies notation specifies the crystallographic point group of the system, which depends on the atomic positions in the primitive cell. If you remove part of the atoms, the crystallographic point group will naturally change, because some symmetry operations will be removed:

- p63/mmc: http://img.chem.ucl.ac.uk/sgp/large/194az1.htm
- p6m2: http://img.chem.ucl.ac.uk/sgp/large/187az1.htm

So, the only thing one can do to retain the p63/mmc space group is to keep the extra layer.

Best,
Daniele

Title: Re: Change in space group
Post by: hsuya on July 4, 2020, 00:48

Okay, thank you :)