# Crystalline aluminum
#
# Determination of the surface energy of aluminum :
# a minimal slab.

#Definition of occupation numbers
occopt 4
tsmear 0.04

#Definition of the k-point grid 
kptopt 1          # Option for the automatic generation of k points, taking
                  # into account the symmetry
ngkpt  4 4 1  
nshiftk 2
shiftk  0.5 0.0 0.0
        0.0 0.5 0.0


#Definition of the unit cell
acell 3*7.50559090E+00   # Lattice parameters of bulk aluminum
rprim  0.5 -0.5  0.0     # The lattice vector along the z direction
       0.5  0.5  0.0     # is doubled with respect to previous run.
       0.0  0.0  2.0     # 

#Definition of the atom types
ntypat 1          # There is only one type of atom
znucl 13          # The keyword "znucl" refers to the atomic number of the 
                  # possible type(s) of atom. The pseudopotential(s) 
                  # mentioned in the "files" file must correspond
                  # to the type(s) of atom. Here, the only type is Aluminum
                         

#Definition of the atoms
natom 3           # Three atoms per cell: three aluminum layers and some vacuum
typat 3*1         # These atoms are of type 1, that is, Aluminum
xred              # This keyword indicate that the location of the atoms
                  # will follow, one triplet of number for each atom
   0.0  0.0  0.0     # Triplet giving the REDUCED coordinate of atom 1.
   0.5  0.5  0.25    # Triplet giving the REDUCED coordinate of atom 2.
   0.0  0.0  0.5     # Triplet giving the REDUCED coordinate of atom 3.
                     # The z-coordinate of the vacuum layer is 0.75 .
 
#The relaxation
ionmov 3
tolmxf 5.0d-4
ntime 10

#Exchange-correlation functional
ixc 1             # LDA Teter Pade parametrization

#Definition of the planewave basis set
ecut  6.0         # Maximal kinetic energy cut-off, in Hartree

#Definition of the SCF procedure
nstep 10          # Maximal number of SCF cycles
toldff 5.0d-5     
