# Input for Positron tutorial
# First step of the tutorial on electron-positron annihilation
# Positron lifetime calculation within PAW
# Si, 2 atoms in the box

#Define the different datasets
ndtset 2          # 2 datasets

#FIRST DATASET
positron1  0      # Dataset 1 is a simple electronic GS calculation

#SECOND DATASET
positron2  1      # Dataset 2 is a positronic GS calculation
getden2    1      #   in presence of the previous electronic density

kptopt2    0      #   Use only k=gamma point

ixcpositron2 1    # We are using the Boronski and Nieminen parametrization

posocc2      1    # Occupation number for the positron
                  #  (should be set <1 for bulk calculation with a small cell).
                  # Here the zero positron density limit is used,
                  #   so results do not depend on posocc.


#-------------------------------------------------------------------------------
#Definition of data common to all datasets

#Definition of the unit cell
acell 3*5.43 angstrom  # Lengths of the primitive vectors (exp. param. in angstrom)
rprim             # 3 orthogonal primitive vectors (FCC lattice)
  0.0 1/2 1/2 
  1/2 0.0 1/2
  1/2 1/2 0.0

#Definition of the atom types and pseudopotentials
ntypat 1          # There is only one type of atom
znucl 14          # Atomic number of the possible type(s) of atom. Here silicon.
pp_dirpath "$ABI_PSPDIR"              # Path to the directory were
                                      #   pseudopotentials for tests are stored
pseudos "Pseudodojo_paw_pw_standard/Si.xml" # Name and location of the pseudopotential
                         
#Definition of the atoms
natom 2           # There are two atoms
typat 1 1         # They both are of type 1, that is, Silicon
xred              # Location of the atoms:
  0.0 0.0 0.0     #  Triplet giving the reduced coordinates of atom 1
  1/4 1/4 1/4     #  Triplet giving the reduced coordinates of atom 2

#Definition of bands and occupation numbers
nband 6           # Compute 6 bands
occopt 1          # Automatic generation of occupation numbers, as a semiconductor

#Numerical parameters of the calculation : planewave basis set and k point grid
ecut 8.           # Maximal plane-wave kinetic energy cut-off, in Hartree
pawecutdg 15.     # Max. plane-wave kinetic energy cut-off, in Ha, for the PAW double grid
kptopt 1          # Automatic generation of k points, taking into account the symmetry
ngkpt 4 4 4       # This is a 4x4x4 grid based on the primitive vectors of the recip. space
nshiftk 1         # We do not shift the grid in order to have Gamma point in it
shiftk 0. 0. 0.

#Parameters for the SCF procedure
nstep 50          # Maximal number of SCF cycles
tolvrs 1.0d-8     # Will stop when, twice in a row, the difference 
                  # between two consecutive evaluations of potential residual 
                  # differ by less than tolvrs 

#Miscelaneous parameters
prtwf 0           # Do not print wavefunctions
prtden 1          # Print density (electronic and/or positronic)
prteig 0          # Do not print eigenvalues
optforces 0       # Forces computation is not relevant here
optstress 0       # Stress tensor computation is not relevant here


##############################################################
# This section is used only for regression testing of ABINIT #
##############################################################
#%%<BEGIN TEST_INFO>
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test =
#%%   tpositron_1.abo, tolnlines=  0, tolabs= 0.0, tolrel= 0.0, fld_options= -easy
#%% [paral_info]
#%% max_nprocs = 10
#%% [extra_info]
#%% authors = J. Wiktor
#%% keywords = POSITRON,PAW
#%% description =
#%%   Input for Positron tutorial
#%%   First step of the tutorial on electron-positron annihilation
#%%   Positron lifetime calculation within PAW
#%%   Si, 2 atoms in the box
#%%<END TEST_INFO>
