# C in diamond structure. 
 ndtset 48 udtset 8 6
 iqpt:? 1               # Index of the first q-point of this file (usefull if you split your 
                        # input files

 elph2_imagden 0.1 eV   # Imaginary shift of the denominator of the sum-over-states 
                        # in the perturbation denominator. Usual value is 0.1 eV to reproduce
                        # experimental broadening at 300K. Increasing the value help the 
                        # convergence with respect to the number of q-points. 
 ngkpt 2 2 2            # k-grid should be at least 4x4x4 for diamond to be converged.
 nshiftk 1
 shiftk 0.0 0.0 0.0
 ngqpt 4 4 4            # Should be converged upon
 qptopt 1
 nshiftq 1
 shiftq 0.0 0.0 0.0

# Ground state density
 iqpt+?    1
 iscf?1    7
 tolvrs?1  1.0d-8   # tolvrs 1.0d-18 should be used for converged results

# Non self-consistent calculation following high sym k path
 getden?2   -1
 iscf?2     -2
 getwfk?2   -1
 tolwfr?2    1.0d-8   # tolwfr 1.0d-22 should be used for converged results
 kptopt?2   -9
 ndivsm?2    5
 kptbounds?2
    1/2 0.0 0.0  # L
    0.0 0.0 0.0  # Gamma
    0.0 1/2 1/2  # X
    1/4 1/2 3/4  # W
    3/8 3/8 3/4  # K
    1/2 1/2 1/2  # L
    1/4 1/2 3/4  # W
    1/2 1/2 1.0  # X
    3/8 3/8 3/4  # K
    0.0 0.0 0.0  # Gamma

# Non self-consistent calculation with an abritrary q point 
 getden?3 -2
 getwfk?3 -2
 iscf?3   -2
 nqpt?3    1
 nbdbuf?3  2
 tolwfr?3  1.0d-8       # tolwfr 1.0d-22 should be used for converged results
 
# Computation at q
 getwfk?4 -3
 getwfq?4 -1
 iscf?4    7
 nqpt?4    1
 ieig2rf?4 1            # Static eigenvalues corrections using DFPT (Sternheimer)
 smdelta?4 1            # Flag required to produce the _EIGI2D used to 
                        # compute the lifetime of electronic levels.
                        # smdelta = 1 ==> Fermi-Dirac smearing.
 nbdbuf?4  2            # 2 buffer bands. RF converges much faster.
 rfphon?4  1            # Do phonon response
 rfatpol?4 1 2          # Treat displacements of all atoms
 rfdir?4   1 1 1        # Do all directions 
 tolwfr?4  1.0d-8       # tolwfr 1.0d-22 should be used for converged results

# Non self-consistent calculation following high sym k path
 nqpt?5      1
 getden?5   -4
 iscf?5     -2
 getwfk?5   -3
 nbdbuf?5    2       # 2 buffer bands. RF converges much faster.
 tolwfr?5    1.0d-8  # tolwfr 1.0d-22 should be used for converged results
 kptopt?5   -9
 ndivsm?5    5
 kptbounds?5
    1/2 0.0 0.0  # L
    0.0 0.0 0.0  # Gamma
    0.0 1/2 1/2  # X
    1/4 1/2 3/4  # W
    3/8 3/8 3/4  # K
    1/2 1/2 1/2  # L
    1/4 1/2 3/4  # W
    1/2 1/2 1.0  # X
    3/8 3/8 3/4  # K
    0.0 0.0 0.0  # Gamma


# Computation at an other q point
 nqpt?6     1
 getden?6  -5
 get1den?6 -2
 getwfk?6  -4
 getwfq?6  -1
 tolwfr?6   1.0d-8  # tolwfr 1.0d-22 should be used for converged results
 nbdbuf?6   2       # 2 buffer bands. RF converges much faster.
 ieig2rf?6  1
 smdelta?6  1
 rfphon?6   1
 rfatpol?6  1 2
 rfdir?6    1 1 1
 iscf?6    -2
 kptopt?6  -9
 ndivsm?6   5
 kptbounds?6
    1/2 0.0 0.0  # L
    0.0 0.0 0.0  # Gamma
    0.0 1/2 1/2  # X
    1/4 1/2 3/4  # W
    3/8 3/8 3/4  # K
    1/2 1/2 1/2  # L
    1/4 1/2 3/4  # W
    1/2 1/2 1.0  # X
    3/8 3/8 3/4  # K
    0.0 0.0 0.0  # Gamma

# Cell dependant parameters
 acell 3*6.675
 rprim 0 .5 .5 .5 0 .5 .5 .5 0
 nsym 1                # Symmetries are not yet sufficiently tested.
                       # Disable symmetries.        
 natom 2
 typat 1 1
 xred 3*0.0 3*0.25
 nband 12
 ntypat 1
 znucl 6
 diemac 6
 ecut 5               # Underconverged ecut. 
 enunit 2
 nstep 50
 istwfk *1