[Wien] After supercell, add impurity... x sgroup change space group

 

Serhat Ayık Sun, 24 Jan 2021 12:32:20 -0800

Dear Wien2k users,
In my original struct file, I have (B Lattice) 3 non equiv. atoms (Chemical
form: AgInS2), space group 122_I-42d, and 8 number of symmetry operations.
I do 2x2x2, P lattice type supercell and I have 48 non equiv. (16 Ag, 16
In, 16 S) atoms. I want chemical form like AgAl(0.5)In(0.5)S2. I am
replacing 8 In atoms with 8 Al atoms. Finally, I have 16 Ag, 8 Al, 8 In and
16 S in struct file.
Then, I do
- x nn (nn-bondlength factor:2)
copy case.struct_nn to case.struct. (After this step, I have 7 atoms "2 Ag,
1 Al, 1 In, 3 S" in case.struct)
- repeat x nn
-  x sgroup
warning: !!! Number of inequivalent atoms has changed. !!! Old value= 48
New value= 7 warning: !!! Unit cell has been reduced.
sgroup found: 17 (P 2 2 21)

I think the space group shouldn't change.
Is it true that the space group changes? Or am I making a mistake somewhere?

Regards 

https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg20783.html