# DGN-f crystall : computation of the of the response to homogeneous
# electric field and atomic displacements, at q=0

ndtset 3

#Dataset 1 : Ground state calculation
irdwfk1 1
kptopt1 1          # Option for the automatic generation of k points,
                   # taking into account the symmetry
#kptrlen1 35.0
tolvrs1  1.0d-18
iscf1 5
nstep 50

#Response Function calculation : d/dk
  rfelfd2   2             # Activate the calculation of the d/dk perturbation
   rfdir2   1 1 1         

    nqpt2   1
     qpt2   0.0 0.0 0.0   # This is a calculation at the Gamma point

  getwfk2   -1            # Uses as input the output wf of the previous dataset

  kptopt2   2             # Automatic generation of k points,
                          # using only the time-reversal symmetry to decrease
                          # the size of the k point set.
  nstep2 200
    iscf2  -3             # The d/dk perturbation must be treated 
                          # in a non-self-consistent way
  tolwfr2   1.0d-22       # Must use tolwfr for non-self-consistent calculations
                          

#Response Function calculation : electric field perturbation and phonons
  rfphon3   1             # Activate the calculation of the atomic dispacement perturbations
  rfatpol3   1 50         # All the atoms will be displaced
  rfelfd3   3             # Activate the calculation of the electric field perturbation
   rfdir3   1 1 1         
   rfstrs3  3
    nqpt3   1
     qpt3   0.0 0.0 0.0   # This is a calculation at the Gamma point

  getwfk3   -2            # Uses as input wfs the output wfs of the dataset 1
  getddk3   -1            # Uses as input ddk wfs the output of the dataset 2
  
  nstep3 50  
  kptopt3   2             # Automatic generation of k points,
                          # using only the time-reversal symmetry to decrease
                          # the size of the k point set.
  tolvrs3   1.0d-8
    iscf3   5             # Self-consistent calculation, using algorithm 5

#Definition of the unit cell
acell 9.670335939244  4.405915099855 10.713119187058 Angstroms  
angdeg 90.0d0  95.98450936d0  90.0d0
spgroup 7

ntypat 4          
znucl 1 6 7 8     

natom 50
natrd 25
#nsym 2
typat 3 2 2 4 4 3 2 2 4 4 3 4 4 4 1 1 1 1 1 1 1 1 1 1 1

xred             
2.1300571476E-01  9.5795498783E-01  3.1543756670E-01
3.2668168801E-01  1.3386510050E-01  2.7307151597E-01
3.7051231089E-01  9.8443258711E-01  1.5854965721E-01
4.6959991559E-01  1.4556486780E-01  1.1315062703E-01
3.1390161952E-01  7.5730999089E-01  1.1340676009E-01
7.7240647600E-01  4.5415725844E-01  1.5011138870E-01
6.6491397903E-01  6.3745594956E-01  2.0268839480E-01
6.2165131841E-01  4.9978665599E-01  3.2364517532E-01
5.2953456361E-01  6.5218953543E-01  3.7100175381E-01
6.7841172355E-01  2.5556286898E-01  3.6092444922E-01
1.0110305553E+00  1.8609883021E-02  4.4599393062E-02
8.6383867556E-02  2.4908786686E-01  5.6995619792E-02
9.8702238265E-01  8.8396522685E-01  9.4236041697E-01
9.6005854677E-01  9.0915373371E-01  1.4165644784E-01
4.1497122315E-01  1.3992787409E-01  3.4524521407E-01
2.9074684520E-01  3.6624551216E-01  2.4651309761E-01
1.3831045624E-01  9.0314461723E-01  2.4184048478E-01
1.5817632172E-01  6.9875769050E-02  3.7991204470E-01
2.5131681127E-01  7.5957014078E-01  3.5567322797E-01
4.9528658687E-01  6.9595456617E-02  3.2579160062E-02
5.7187848043E-01  6.3980727470E-01  1.3599413329E-01
7.0897117875E-01  8.6611981331E-01  2.2155000393E-01
8.0445608425E-01  2.9442700232E-01  2.1769860866E-01
8.5510823698E-01  5.9599485811E-01  1.3042337560E-01
7.3556229958E-01  3.4430594622E-01  6.9295049342E-02

#Definition of the planewave basis set

ecut    25.0           # Maximal kinetic energy cut-off, in Hartree

#Definition of the SCF procedure

Diemac 1.7            # 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).