I recommend using ASE for doing this. In a Jupyter notebook (although you can use plain Python)

from ase import Atoms

from ase.io import read,write

atoms=read('CeO2.cif',format='cif',store_tags=True,primitive_cell=True,subtrans_included=False)

atoms444=atoms*(4,4,4)

atoms444.write('CeO2.4x4x4.xyz',format='xyz')

The xyz file would contain the 192 atomic positions.

Regards,

Roberto

Roberto D'Agosta

Thank you for your suggestions. I have generated the xyz file of 192 atoms using the code. But the lattice parameter its showing different:

Title XYZ file

Lattice type P

Space group name P 1

Space group number 1

Setting number 1

Lattice parameters

a b c alpha beta gamma

1.00000 1.00000 1.00000 90.0000 90.0000 90.0000

Unit-cell volume = 1.000000 Å^3

But it should be as follows according to CIF file:

Title Ce O2

Lattice type F

Space group name F m -3 m

Space group number 225

Setting number 1

Lattice parameters

a b c alpha beta gamma

5.40730 5.40730 5.40730 90.0000 90.0000 90.0000

Unit-cell volume = 158.103467 Å^3

Can you explain it please?

The standard xyz file does not contain information bout the unit cell. Either export a cif file

atoms444.write('CeO2.4x4x4.cif',format=’cif')

or an extended xyz

atoms444.write('CeO2.4x4x4.xyz',format='extxyz’)

and try again with Vesta.

Roberto D'Agosta Thank you so much for your answer. So the CIF I have uploaded it has conventional unit cell of CeO2 (not primitive), Should we convert the structure into primitive and then run the ase comments? In the code when you mention primitive_cell=true what does it mean? Will it convert the conventional cell into primitive cell?

I would first convert to the primitive cell and then do the scaling up. In any case, in the conventional cell there are 12 atoms, and you need 16 cells to get 192 atoms. Now you have a few combinations that can give 16 but none of them is symmetric in the 3 directions as your initial construction seemed to imply.

primitive_cell=True

does exactly that.

Regards,

Roberto