# H2 molecule in a big box
#
# In this input file, the location of the information on this or that line
# is not important : a keyword is located by the parser, and the related
# information should follow. Still, this file is strongly structured, for pedagogical purpose.
# The "#" symbol indicates the beginning of a comment : the remaining
# of the line will be skipped.

#Definition of the unit cell
acell 10 10 10    # The keyword "acell" refers to the
                  # lengths of the primitive vectors (in Bohr)
#rprim 1 0 0  0 1 0  0 0 1 # This line, defining orthogonal primitive vectors,
                           # is commented, because it is precisely the default value of rprim

#Definition of the atom types and pseudopotentials
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. 
                  # Here, the only type is Hydrogen. The pseudopotential(s) 
                  # mentioned after the keyword "pseudos" should correspond to this type of atom.
pp_dirpath "$ABI_PSPDIR"                 # This is the path to the directory were pseudopotentials for tests are stored
pseudos "Pseudodojo_nc_sr_04_pw_standard_psp8/H.psp8"  # Name and location of the pseudopotential
                  # This pseudopotential comes from the pseudodojo site http://www.pseudo-dojo.org/  (NC SR LDA standard),
                  # and was generated using the LDA exchange-correlation functional (PW=Perdew-Wang, ixc=-1012). 
                  # By default, abinit uses the same exchange-correlation functional than the one of the input pseudopotential(s)

#Definition of the atoms
natom 2           # There are two atoms
typat 1 1         # They both are of type 1, that is, Hydrogen
xcart             # This keyword indicates that the location of the atoms
                  # will follow, one triplet of number for each atom
  -0.7 0.0 0.0    # Triplet giving the cartesian coordinates of atom 1, in Bohr
   0.7 0.0 0.0    # Triplet giving the cartesian coordinates of atom 2, in Bohr

#Numerical parameters of the calculation : planewave basis set and k point grid
ecut 10.0         # Maximal plane-wave kinetic energy cut-off, in Hartree
kptopt 0          # Enter the k points manually 
nkpt 1            # Only one k point is needed for isolated system,
                  # taken by default to be 0.0 0.0 0.0

#Parameters for 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) 
                  # This value is way too large for most realistic studies of materials
diemac 2.0        # 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

##############################################################
# This section is used only for regression testing of ABINIT #
##############################################################
#%%<BEGIN TEST_INFO>
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test = 
#%%   tbase1_1.abo, tolnlines=  0, tolabs=  0.000e+00, tolrel=  0.000e+00
#%% [paral_info]
#%% max_nprocs = 1
#%% [extra_info]
#%% authors = X. Gonze
#%% keywords = 
#%% description = H2 molecule in a big box
#%%<END TEST_INFO>
