#Structural optimisation

#ndtset 6    jdtset 1 2 3 4 5 6

#  ngkpt1  6  6  6
#  ngkpt2  8  8  8
#  ngkpt3 10 10 10
#  ngkpt4 12 12 12
#  ngkpt5 14 14 14
#  ngkpt6 16 16 16

  ngkpt  6  6  6   # In the present example, only this grid of k points is considered
                   # A full convergence study on k points should be done, see the above lines.

#Definition of the unit cell
#**********************************
acell 3*10.53
rprim
0 1/2 1/2
1/2 0 1/2
1/2 1/2 0

#Definition of the atom types and pseudopotentials
 ntypat 2 # two types of atoms
 znucl 15 13 # the atom types are Phosphorous and Aluminum

# the following norm-conserving pseudopotentials are stored in the abinit distribution, but are freely
# available through www.pseudo-dojo.org
# this set uses the Perdew-Wang parameterization of LDA for the xc model
 pp_dirpath "$ABI_PSPDIR"
 pseudos "Psdj_nc_sr_04_pw_std_psp8/P.psp8, Psdj_nc_sr_04_pw_std_psp8/Al.psp8"

#Definition of the atoms
 natom 2 # two atoms in the cell
 typat 1 2 # type 1 is Phosphorous, type 2 is Aluminum (order defined by znucl above and pseudos list)
 nband 4 # nband is restricted here to the number of filled bands only, no empty bands.
 nbdbuf 0

# atomic positions in units of cell vectors
xred
1/4 1/4 1/4
0 0 0

#Numerical parameters of the calculation : planewave basis set and k point grid
ecut  2.8 # this value is very low but is used here to achieve very low calculation times.
        # in a production environment this should be checked carefully for convergence and
        # a more reasonable value is probably around 30
ecutsm 0.5
dilatmx 1.05
nshiftk 4 # this Monkhorst-Pack shift pattern is used so that the symmetry of the shifted grid
          # is correct. A gamma-centered grid would also have the correct symmetry but would be
          # less efficient.
shiftk 0.5 0.5 0.5
       0.5 0.0 0.0
       0.0 0.5 0.0
       0.0 0.0 0.5

# scf parameters
nstep 8  # limit number of steps for the tutorial, in general this should be set to its
         # default (30) or higher

# suppress printing of density, wavefunctions, etc except what is
# explicitly requested above in the ndtset section
prtwf 0
prtden 0
prteig 0

#Structural relaxation
#*********************
   geoopt "bfgs"
   optcell 2
   tolvrs 1.0d-15
   tolmxf 5.0d-6
   ntime 100

##############################################################
# This section is used only for regression testing of ABINIT #
##############################################################
#%%<BEGIN TEST_INFO>
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test =
#%%   tnlo_1.abo, tolnlines=  1, tolabs=  4.192e-06, tolrel=  8.000e-05, fld_options=-medium
#%% [paral_info]
#%% max_nprocs = 2
#%% [extra_info]
#%% authors = J. Zwanziger, M. Veithen, P. Ghosez
#%% keywords =
#%% description = Structural optimisation
#%%<END TEST_INFO>