# H2 molecule in a big box
#
# This file will optimize automatically the interatomic distance

#Define the methodology to find the minimum
ionmov  2              # Use the modified Broyden algorithm
ntime   10             # Maximum number of Broyden "timesteps"
tolmxf  5.0d-4         # Stopping criterion for the geometry optimization : when 
                       # the residual forces are less than tolmxf, the Broyden 
                       # algorithm can stop
xcart  -0.7   0.0 0.0  # The starting values of the
        0.7   0.0 0.0  # atomic coordinates

tolrff  0.02           # Will stop the SCF cycle when, twice in a row, 
                       # the ratio between the absolute maximal change of force in the SCF loop
                       # and the largest force is smaller than tolrff


nband    1             # Only one band is occupied. In order to get the energy,
                       # forces ..., there is no need to compute more than one band.

#-------------------------------------------------------------------------------
#The rest of this file is similar to the tbase1_1.in file, except
#that xcart has been moved above, and that toldfe has been replaced
#by toldff, see above.

#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

#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 is no more defined, as toldff is used above... 
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_3.abo, tolnlines=  3, tolabs=  3.0e-10,   tolrel=  2.000e-08
#%% [paral_info]
#%% max_nprocs = 1
#%% [extra_info]
#%% authors = X. Gonze
#%% keywords = 
#%% description = 
#%%   H2 molecule in a big box
#%%   This file will optimize automatically the interatomic distance
#%%<END TEST_INFO>
