System: fcc Pt (001), 4layers
ISTART = 0 
EDIFF = 1e-6              # electronic convergence 
PREC = High
IBRION = 1                # DIIS algorithm
NSW = 10
EDIFFG = -0.01            # max forces: 0.1eV/AA
ELMIN = 5                 # at least 5 el. scf steps  for each ionic step
ENCUT =  300.0            # keep ENCUT from a_0 optimization
IMAGES = 2                # 2 intermediate geometries for 
SPRING = -5               # spring constant 
