Step 1. Based on the equilibrium configuration, generate_all_slabs module in pymatgen.core.surface would help to generate surface structure list with using max_miller, min_slab_size, and min_vacuum_size parameters.
Step 2. If refine is True, we do refine process. If reprod-opt is True (the default is False), we do reproduce process. Otherwise, the surface structure (POSCAR) with perturbations in xz and miller index information (miller.out) are written in the task directory, for example, in confs/mp-*/interstitial_00/task.000000 with the check and possible removing of the old input files like before.