# Crystalline AlAs : computation of the phonon spectrum

   ndtset   1
#Set 1 : ground state self-consistency

  getwfk1   0            # Cancel default
  kptopt1   1            # Automatic generation of k points, taking
                         # into account the symmetry
    nqpt1   0            # Cancel default
  tolvrs1   1.0d-18      # SCF stopping criterion (modify default)
  rfphon1   0            # Cancel default
 
#Q vectors for all datasets

#Complete set of symmetry-inequivalent qpt chosen to be commensurate
# with kpt mesh so that only one set of GS wave functions is needed.
#Generated automatically by running GS calculation with kptopt=1,
# nshift=0, shiftk=0 0 0 (to include gamma) and taking output kpt set
# file as qpt set. Set nstep=1 so only one iteration runs.

     nqpt   1            # One qpt for each dataset (only 0 or 1 allowed)
                         # This is the default for all datasets and must
                         #  be explicitly turned off for dataset 1.

#     qpt2   0.00000000E+00  0.00000000E+00  0.00000000E+00
#     qpt3   0.00000000E+00  0.00000000E+00  0.00000000E+00   # Gamma point
#     qpt4   0.00000000E+00  0.00000000E+00  1.00000000E-01   # 
#     qpt5   0.00000000E+00  0.00000000E+00  2.00000000E-01
#     qpt6   0.00000000E+00  0.00000000E+00  3.00000000E-01
#     qpt7   0.00000000E+00  0.00000000E+00  4.00000000E-01
#     qpt8   0.00000000E+00  0.00000000E+00  5.00000000E-01   # near Z point
   
#Set 2 : Response function calculation of d/dk wave function 

#    iscf2   -3         # Need this non-self-consistent option for d/dk
#  kptopt2   2          # Modify default to use time-reversal symmetry
#  rfphon2   0          # Cancel default
#  rfelfd2   2          # Calculate d/dk wave function only
#  tolvrs2   0.0        # Cancel default for d/dk
#  tolwfr2   1.0d-22    # Use wave function residual criterion instead

#Set 3 : Response function calculation of Q=0 phonons and electric field pert.

#  getddk3   2          # d/dk wave functions from last dataset
#  kptopt3   2          # Modify default to use time-reversal symmetry
#  rfelfd3   3          # Electric-field perturbation response only

#Sets 4-10 : Finite-wave-vector phonon calculations (defaults for all datasets)

#   getwfk   1          # Use GS wave functions from dataset1
#   kptopt   3          # Need full k-point set for finite-Q response
#   rfphon   1          # Do phonon response
#  rfatpol   1 20       # Treat displacements of all atoms
#    rfdir   1 1 1      # Do all directions (symmetry will be used)
#   tolvrs   1.0d-8     # This default is active for sets 3-10

#######################################################################
#Common input variables

#Definition of the unit cell
    acell 15.0 15.0 2.4488692126 angstrom          
    angdeg 90 90 90

#Definition of the atom types
   ntypat   1         # There are two types of atom
    znucl   6         # 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, type 1 is the carbon

#Definition of the atoms
    natom   20         # There are two atoms
    typat   20*1       # The first is of type 1 (C)
                       
    xangst   -8.0924335049E-01 -3.3163570512E+00  6.1221710237E-01
              6.0804942849E-01 -3.3590539123E+00  6.1221710237E-01
              1.2944624713E+00 -3.1586214133E+00 -6.1221750391E-01
              2.4660961636E+00 -2.3599952549E+00 -6.1221750391E-01
              2.9035889495E+00 -1.7943663603E+00  6.1221710237E-01
              3.3821026584E+00 -4.5962149940E-01  6.1221710237E-01
              3.4036444664E+00  2.5513173946E-01 -6.1221750391E-01
              3.0063904129E+00  1.6162745470E+00 -6.1221750391E-01
              2.6037571224E+00  2.2072261565E+00  6.1221710237E-01
              1.4823424232E+00  3.0749577849E+00  6.1221710237E-01
              8.0924302567E-01  3.3163586696E+00 -6.1221750391E-01
             -6.0804973407E-01  3.3590557843E+00 -6.1221750391E-01
             -1.2944626898E+00  3.1586230859E+00  6.1221710237E-01
             -2.4660958642E+00  2.3599962563E+00  6.1221710237E-01
             -2.9035884507E+00  1.7943672691E+00 -6.1221750391E-01
             -3.3821024396E+00  4.5962258296E-01 -6.1221750391E-01
             -3.4036445704E+00 -2.5513059456E-01  6.1221710237E-01
             -3.0063909822E+00 -1.6162734832E+00  6.1221710237E-01
             -2.6037577315E+00 -2.2072250790E+00 -6.1221750391E-01
             -1.4823428329E+00 -3.0749564138E+00 -6.1221750391E-01

       
#Gives the number of band, explicitely (do not take the default)
    nband   54         

#Exchange-correlation functional

      ixc   1             # LDA Teter Pade parametrization
   occopt   6
   tsmear   0.04  

#Definition of the planewave basis set

     ecut   40.0           # Maximal kinetic energy cut-off, in Hartree

#Definition of the k-point grid
    ngkpt   1  1  16          
   nshiftk   1              # Use one copy of grid only (default)
   shiftk   0.0 0.0 0.5    # For number of k points be just twice in time-symmetry on&off


#Definition of the SCF procedure
     iscf   7          # Self-consistent calculation, using algorithm 4: Anderson, mix with 2 pervious steps
    npulayit 5
    nstep   400        # Maximal number of SCF cycles
#   diemac   9.0        # 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.
                       # The dielectric constant of AlAs is smaller that the one of Si (=12).
    diemix  0.33