I am very new for lammps. I want simulate iron core Iron oxide structure. I know there are many things need to run the simulation. but for the beginning i need the geometry structure of iron core iron oxide.
Thank you very much for your response. You have mention to that import the unit cell but how should I get unit cell for import. Because I never used ovito so before learning the ovito, i should make sure that it will work for me.
I have tried your steps and Avogadro and then ovito and load file but did not get show periodic images" "expression select" and "delete selected atoms".