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[Qiang Xu <xuqiang@ntu.edu.sg>]

Dear Prof. Matteo Giantomassi,

Thanks a lot.


Qiang Xu 
Division of Microelectronics
School of Electrical & Electronic Engineering
Nanyang Technological University
Singapore





On 24/11/2008 4:38 PM, "Matteo Giantomassi"
<Matteo.Giantomassi@uclouvain.be> wrote:



> Dear All,
>
> I tried to calculate the Sn band structure using GW correction.  The
> following is my test  input file:
>

> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
> # 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
> nspinor 2
>

Noncollinear magnetism + spin-orbit is not implemented in the GW part.
We are working on it but the treatment of the spin-orbit coupling
requires several changes in the code that are not so straightforward.
At present the implementation of this feature is not among our priorities,
neither for version 5.7 nor for 5.8.
Maybe a preliminary implementation will be released in version 6.0 but
you have to wait a bit.

Best regards,
Matteo Giantomassi

> # 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
> nkpt2    19             # A set of 19 k-points containing Gamma
> nshiftk2  4
> shiftk2  0.0 0.0 0.0  # This grid contains the Gamma point
>          0.0 0.5 0.5
>          0.5 0.0 0.5
>          0.5 0.5 0.0
> istwfk2  19*1                    # Option needed for Gamma
> iscf2    -2             # Non self-consistent calculation
> getden2  -1             # Read previous density file
> nband2   20
> nbandkss2 100        # Number of bands to store in KSS file
> kssform   3
>
> # Dataset3: Calculation of the screening (epsilon^-1 matrix)
> optdriver3  3        # Screening calculation
> getkss3     -1       # Obtain KSS file from previous dataset
> nband3      50       # 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
> inclvkb3   0
>
> # 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    0.000    0.000    # (Gamma)
> bdgw4       8  9             # calculate GW corrections for bands from 4
> to 5
>
> # Definition of the unit cell: fcc
> acell  3*12.2435        # 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 50          # 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
>
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
>
> The pseudopotential is 50sn.4.hgh. The log file shows that:
>
>   Unknown:^@^@^@^@^@^@^@^@^@^@ BUG-
>   nspden and nspinor=1 not implemeted yet
>   Action : contact ABINIT group.
>
> I don't find relational help and tutorial in ABINITweb. Can you help me
> with this issue?
>
> Regards
>
>
> Qiang Xu
> Division of Microelectronics
> School of Electrical & Electronic Engineering
> Nanyang Technological University
> Singapore
>