# H atom in a big box
#
# Same file as t11.in, except that natom, typat, and xcart were changed,
# and that the input variables nband, nsppol, occ and occopt are used.


nsppol 2          # Allow a spin-polarized calculation
occopt 2          # Allow occupation numbers to be set by hand
nband  1 1        # Number of bands for spin up and spin down
occ    1.0  0.0   # Occupation numbers for spin up state and spin down state.
                  # The spin up state is occupied, not the spin down state.
spinat 0.0 0.0 1.0  # Gives an initial estimation of the spin on the atom (easy)



#Definition of the unit cell
acell 10 10 10    # The keyword "acell" refers to the
                  # lengths of the primitive vectors (in Bohr)

#Definition of the atom types
ntypat 1          # There is only one type of atom
znucl 1           # 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 Hydrogen.
                         

#Definition of the atoms
natom 1           # There is one atom
typat 1           # This atom is of type 1, that is, Hydrogen
xcart             # 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 coordinates of atom 1, in Bohr

#Definition of the planewave basis set
ecut 10.0         # Maximal kinetic energy cut-off, in Hartree

#Definition of the k-point grid
nkpt 1            # Only one k point is needed for isolated system,
                  # taken by default to be 0.0 0.0 0.0

#Definition of the SCF procedure
nstep 10          # Maximal number of SCF cycles
toldfe 1.0d-6     # Will stop when, twice in a row, the difference 
                  # between two consecutive evaluations of total energy 
                  # differ by less than toldfe (in Hartree) 
diemac 1.0        # Although this is not mandatory, it is worth to
                  # precondition the SCF cycle. The model dielectric
                  # function used as the standard preconditioner
                  # is described in the "dielng" input variable section.
                  # Here, we follow the prescriptions for molecules 
                  # in a big box
