Step 1: vc-relax calculations for lattice parameter
Step 2: scf calculation [for wavefunctions]
mpirun -np 2 pw.x -inp scf.in > scf.out
Step 3: nscf calculations with more K_POINTS
mpirun -np 2 pw.x -inp nscf.in > nscf.out
Step 4: DOS calculations
dos.x < dos.in > dos.out
Step 5: plot DOS using gnuplot