# Crystalline aluminum : optimization of the lattice parameter
#Definition of occupation numbers
occopt 3
tsmear 0.2 eV
ixc 11
ngfft 32 32 32
nband 10
#Definition of the k-point grids
kptopt 0
nkpt 28
kpt
   0.083333  0.083333  0.083333 
   0.083333  0.166667  0.166667 
   0.166667  0.166667  0.250000 
   0.250000  0.250000  0.250000 
   0.083333  0.250000  0.250000 
   0.166667  0.250000  0.333333 
   0.250000  0.333333  0.333333 
   0.250000  0.250000  0.416667 
   0.333333  0.333333  0.416667 
   0.416667  0.416667  0.416667 
   0.083333  0.333333  0.333333 
   0.166667  0.333333  0.416667 
   0.250000  0.416667  0.416667 
   0.250000  0.333333  0.500000 
   0.333333  0.416667  0.500000 
   0.416667  0.500000  0.500000 
   0.333333  0.333333  0.583333 
   0.416667  0.416667  0.583333 
   0.083333  0.416667  0.416667 
   0.166667  0.416667  0.500000 
   0.250000  0.500000  0.500000 
   0.250000  0.416667  0.583333 
   0.333333  0.500000  0.583333 
   0.333333  0.416667  0.666667 
   0.083333  0.500000  0.500000 
   0.166667  0.500000  0.583333 
   0.250000  0.583333  0.583333 
   0.250000  0.500000  0.666667 

wtk
1
3
3
1
3
6
3
3
3
1
3
6
3
6
6
3
3
3
3
6
3
6
6
6
3
6
3
6
nshiftk 4
shiftk  0.5 0.5 0.5  # These shifts will be the same for all grids
        0.5 0.0 0.0
        0.0 0.5 0.0
        0.0 0.0 0.5
ngkpt  4 4 4 

#Definition of the unit cell
acell 4.04 4.04 4.04 Angstrom
rprim  0.0  0.5  0.5   # FCC primitive vectors (to be scaled by acell)
       0.5  0.0  0.5   
       0.5  0.5  0.0

#Optimization of the lattice parameters
#optcell 1
#ionmov  3
#ntime  10
#dilatmx 1.15
#ecutsm  0.5

ntypat 1          
znucl 13         
natom 1               # There is only one atom per cell
typat 1                # This atom is of type 1, that is, Aluminum.
xred 0.0  0.0  0.0    # This keyword indicate that the location of the atoms
ecut  25         # Maximal kinetic energy cut-off, in Hartree
nstep 10          # Maximal number of SCF cycles
toldfe 1.0d-6 eV     # Will stop when, twice in a row, the difference 
                  # between two consecutive evaluations of total energy 
                  # differ by less than toldfe (in Hartree)