I want to simulate a fcc-bcc multilayer system within Lammps. I have written an input file for FeNi, but when I carry out the energy minimization, the atoms for both Fe and Ni are compressed very much and the layers are no longer bcc or fcc. I don't know if this trend is ordinary. if no, I don't know if the initial atomistic structure is incorrect or the problem is interatomic potential.

I will be very grateful if someone checks my input and guides me about the details of making the multilayer structures.