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[Yusia Rosee <yrosee@gmail.com>]

Hi, Dear Yang Ming,

If you want to calculate the GW correction of X(0.0, 0.5,05) point,  
this k point should be one of the k point list in the first step. 
Otherwise it can not calculate for it.

Yusia




mingyang@nus.edu.sg wrote:
> Dear All,
>
> I am a new one of ABINIT. I tried to get GW correction of Si band gap at X 
> point, but encoutered a problem. Might any one there give me a hand?
>
> The error reported in log file is following:
>  
>  sigma : using b1gw and b2gw =            4           5
>
>  findk : check if the k-points for sigma are in the set of BZ
>
>  findk : ERROR -
>  k-point  0.000  0.500  0.500  not in the set of kbz
>
>  leave_new : decision taken to exit ...
> __________________
>
> And, the following is my input file:
>
> # Crystalline silicon
> # Calculation of the GW correction to the direct band gap in Gamma
> # Dataset 1: ground state calculation
> # Dataset 2: calculation of the kss file
> # Dataset 3: calculation of the screening (epsilon^-1 matrix for W)
> # Dataset 4: calculation of the Self-Energy matrix elements (GW corrections)
>
> ndtset      4
>
> kptopt   1            # Option for the automatic generation of k points
> ngkpt    4 4 4        # Density of k points
>
> # Dataset1: usual self-consistent ground-state calculation
> # Definition of the k-point grid
> nkpt1    10
> nshiftk1  4
> shiftk1  0.5 0.5 0.5  # This grid is the most economical
>          0.5 0.0 0.0
>          0.0 0.5 0.0
>          0.0 0.0 0.5
> prtden1  1         # Print out density
>
>
> # Dataset2: calculation of kss file
> # Definition of k-points
> nbandkss2 -1
> npwkss2 0
> iscf2    -2             # Non self-consistent calculation
> getden2  -1             # Read previous density file
> # Dataset3: Calculation of the screening (epsilon^-1 matrix)
> optdriver3  3        # Screening calculation
> getkss3     -1       # Obtain KSS file from previous dataset
> nband3      25       # Bands to be used in the screening calculation
> ecutwfn3    3.6      # Planewaves to be used to represent the wavefunctions
> ecuteps3    6.0      # Dimension of the screening matrix
> ppmfrq3    16.7 eV  # Imaginary frequency where to calculate the screening
>
> # Dataset4: Calculation of the Self-Energy matrix elements (GW corrections)
> optdriver4  4        # Self-Energy calculation
> getkss4     -2       # Obtain KSS file from dataset 1
> getscr4     -1       # Obtain SCR file from previous dataset
> nband4      100      # Bands to be used in the Self-Energy calculation
> ecutwfn4    5.0      # Planewaves to be used to represent the wavefunctions
> ecutsigx4    6.0      # Dimension of the G sum in Sigma_x
>                      # (the dimension in Sigma_c is controlled by npweps)
> nkptgw4      1                # number of k-point where to calculate the GW 
> correction
> kptgw4                       # k-points
>   0.000    0.500  0.500    # (X)
> bdgw4       4  5             # calculate GW corrections for bands from 4 to 5
>
>
> # Definition of the unit cell: fcc
> acell  3*10.217        # This is equivalent to   10.217 10.217 10.217
> rprim  0.0  0.5  0.5   # FCC primitive vectors (to be scaled by acell)
>        0.5  0.0  0.5
>        0.5  0.5  0.0
>
> # Definition of the atom types
> ntypat  1         # There is only one type of atom
> znucl 14          # 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, the only type is Silicon.
>
> # Definition of the atoms
> natom 2           # There are two atoms
> typat  1 1        # They both are of type 1, that is, Silicon.
> xred              # Reduced coordinate of atoms
>       0.0  0.0  0.0
>       0.25 0.25 0.25
>
> # Definition of the planewave basis set (at convergence 16 Rydberg 8 Hartree)
> ecut 8.0          # Maximal kinetic energy cut-off, in Hartree
>
> # Use only symmorphic operations
> symmorphi 0
>
> # Definition of the SCF procedure
> nstep   10        # Maximal number of SCF cycles
> diemac  12.0      # 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.
>                   # Here, we follow the prescription for bulk silicon.
> tolwfr  1.0d-10
>
> # This line added when defaults were changed (v5.3) to keep the previous, old 
> behaviour
>   iscf 5
>
> ____________
>
> Thanks.
>
> Best regards,
> Yang Ming
>