SYSTEM = Layers spacing optimization

#Run parameters
 ISTART = 0
 ICHARG = 2
 ISYM = 0
 ISPIN = 1              ! Not Spin-Polarized
 LWAVE = .FALSE.
 LCHARG = .FALSE.
 PREC = Accurate
 ALGO = F
 ISMEAR = -1
 SIGMA = 0.1

 IBRION = 2
 ISIF = 2               ! keep cell shape and volume fixed while relaxing atoms

 ENCUT = 450
 EDIFF = 1e-07          ! SCF treshold (energy)
 EDIFFG = -0.001        ! optg treshold (force)
 NSW = 100

#Functional
 GGA = ML               ! Use the rPW86 exchange 
 LUSE_VDW = .TRUE.      ! Use the vdW correlation
 Zab_vdw  = -1.8867     ! Use vdwDF2 instead of vdwDF
 AGGAC = 0.0000         ! Don't use the std GGA correlation 

 KPAR = 1
 NPAR = 2