[Wien] How to get the good monoclinic structure accepted by Wien2k code from cif file

 

[Wien] Structure optimization of a monoclinic lattice

shamik chakrabarti Sat, 26 Jun 2021 06:23:33 -0700

Dear Wien2k users,

                          I am trying to do ABC & Gamma optimization of a
monoclinic lattice. At the cif file of the structure, the angle Beta was
greater than 90 while Alpha & Gamma were 90 degree. To incorporate with the
usual formalism of wien 2k I have changed the angle Beta to Gamma & Gamma
to Beta. I have also alternate b to c & c to b & also y-coordinates to z
coordinates & z coordinates to y-coordinates. However, with this changed
struct file when I saved the structure (file attached) the warning is
coming as " space group is not consistent with cell parameters" & I not
able to move further.

Any response will be appreciated.

Thanks in advance,

with regards,
-- 
Dr. Shamik Chakrabarti
Research Fellow
Department of Physics
Indian Institute of Technology Patna
Bihta-801103
Patna
Bihar, India

NaSb_ABC.struct
Description: Binary data

 

 Re: [Wien] Structure optimization of a monoclinic lattice

Gavin Abo Sat, 26 Jun 2021 07:27:50 -0700

I cannot remember for sure, but I think WIEN2k might need you to use 14_P21/a spacegroup setting in StructGen.  It looks like your struct file in StructGen has 14_P21/c.

Have you perhaps went to:

https://materialsproject.org/materials/mp-7944/#

Click CIF next to Final Structure and click on Symmetrized to download NaSb_mp-7944_symmetrized.cif

Then, did you go to:

https://jp-minerals.org/vesta/en/download.html

Download VESTA.

Then, open VESTA 3.5.7 and drag/drop NaSb_mp-7944_symmetrized.cif into it.

Click Edit -> Edit Data -> Unit Cell

Select "P 21/a (Unique axis c)"

Click Apply, then click OK

Click File -> Export Data and Save as NaSb.cif

Finally, get NaSb.struct using:

cif2struct NaSb.cif

If you have not done that, maybe give that a try.

That should be because sgroup requires that you use the "14 [P 21/c] [unique axis c] [cell choice 1]" setting. The sgroup program uses coded names according to the International Tables 1992 [ http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg08153.html ].  I believe "14 [P 21/c] [unique axis c] [cell choice 1]" may be equivalent to "P 21/a (Unique axis c)".