I am new to Quantum espresso calculation. My structure is a High entropy oxide with a 3x1x1 supercell. I want to undergo DFT calculation by considering it as an FCC crystal structure. Still, if I mention ibrav=3 in the quantum espresso input file, It shows an error because of the different lattice parameters due to the supercell.
I have continued my calculation using ibrav=0, but after relaxation, the structure changed to orthorhombic. Could anyone help me with this thing to rectify the problem?