POSCAR file for supercell..

[Dhanish Sidhik]

Hi,

I need to make an Al-10at% Si phase, which is a gamma phase to calculate its thermomechanical properties. The structure is FCC. This is how I tried to make the system.

1. Make Al- 3x3x3 supercell
2. I removed 10 Aluminium atoms and replaced 10 Si atoms in it. From poscar text file, i changed Al number to 98 and Si to 10- to make approximately 10 % Si atom in the system.
3. But now the whole structure has changed to triclinic. The phase i want is gamma phase with FCC structure. why this happens?? how can I make an FCC structure of this phase ??

[alexey.tal]

Dear Dhanish Sidhik,

Thank you for your question.

The procedure you describe for creating a structure seems correct. Please note that you need to make sure that it is compatible with the POTCAR file, i.e., the order of potentials and elements is the same in both files. Also, if you want to restrict the shape of your cell during the relaxation you need to select the corresponding value for the ISIF flag.

Regarding the phase, I am not familiar with this system, so perhaps other users who are familiar with the topic can give you some advice on how to approach it.

Best wishes,
Alexey