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["Dr. Thanusit Burinprakhon" <thanusit@kku.ac.th>]

Dear Zheng

There seems to be some of your input variables that may cause the trouble.

Point-1:
> # Definition of the unit cell: fcc
> acell  3*22.487741        # This is equivalent to   10.217 10.217 10.217
> rprim  1.0  0.0  0.0   # FCC primitive vectors (to be scaled by acell)
>        0.0  1.0  0.0
>        0.0  0.0  1.0

For Si, the above input should be
# 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

Point-2:
 > # Definition of the atom types
> ntypat  2         # There is only one type of atom
> znucl 14   1      # The keyword "znucl" refers to the atomic number of the

The above inputs  should be
ntypat  1         # There is only one type of atom
znucl 14         # Z number of Si

Point-3 :
> # Definition of the atoms
> natom  5          # There are two atoms
> typat  1 4*2        # They both are of type 1, that is, Silicon.
> xcart             # Reduced coordinate of atoms
>     9.4486306   9.4486306   9.4486306
>    11.0743720  11.0743720  11.0743720
>     7.8228893   7.8228893  11.0743720
>     7.8228893  11.0743720   7.8228893
>    11.0743720   7.8228893   7.8228893

Not sure if above is another way of specifying definition of atoms. But
what certainly works is

natom 2           # There are two atoms
typat  1  1        # They both are of type 1, that is, Silicon.
xred                 # Reduced coordinate of atoms
      0.00    0.00  0.00
      0.25    0.25  0.25

Also, please check you k point grid for SCF calculation, it does look
starange to me. But I'm not sure if it's not right. Anyway, make sure
that the k-point grids contains Gamma point which is used in th GW
calculation.

At last,try the test tgw1_2 is a good idea.

Hope this helps.

Kind Regards,
Thanusit Burinprakhon