preferably relaxed structure suitable for DFT input (with ~15 Å vacuum)? I need the atomic positions and lattice vectors for setting up first-principles calculations. Thanks in advance!
The best method to create an input for DFT, but for Quantum ESPRESSO, is BURAI software. Although it only works for QE, I think it is the best free software to create a slab. It's much easier than any other software I tried. I can help you with this.