ABINIT Discussion Forums

Dear All,

I am doing optical properties calculation on graphene with ABINIT+YAMBO with ABINIT used to generate *.KSS file for YAMBO.
However, I got a problem:
1) I can get the correct band strcuture (see the input file "c_band.in" and the output file "co_DS2_EIG_band" attached). I think the kpt #41 is the Dirac point K of graphene (96 kpts in total);
------------------------------------------------------------------------------------------------
kpt# 41, nband= 10, wtk= 1.00000, kpt= -0.3333 0.6667 0.0000 (reduced coord)
-14.44303 -14.44172 -12.69542 -2.07117 -2.06931 8.36134 10.87751 10.87819
------------------------------------------------------------------------------------------------
2) I used the attached file "c_kss.in" to generate the *.KSS file, and it also gave a energy-momentum file "co_DS2_EIG_kss", which shows 44 kpts in total. From "co_DS2_EIG_kss", I do not know which kpt is the Dirac point K of graphene;
-------------------------------------------------------------------------------------------------
kpt# 44, nband=350, wtk= 0.01500, kpt= 0.3500 0.3000 0.0000 (reduced coord)
-14.75397 -14.25776 -12.53084 -2.51367 -1.63779 8.41189 10.67722 10.80666
-------------------------------------------------------------------------------------------------
3) After YAMBO initialization, it generated a file "r_setup", in which the Fermi level is set at zero. In "r_setup", the top of valence band at the kpt #44 (44 in total) is set as 0.0. However, the bottom of conduction band shows a finite value instead of 0.0.
------------------------------------------------------------------------------------------------
*X* K [44] : -0.05000 -1.125833 0.000000 (iku) * Comp.s 5313 * weight 0.01500
E -12.24031 -11.74409 -10.01717 0.00000 0.87588 10.92556 13.19088 13.32033
------------------------------------------------------------------------------------------------

So, my question is that why I can find a gap in "co_DS2_EIG_kss" and "r-setup"?
Attached please find all of the files mentioned above.

Thanks a lot!!!

The other files

Well, the definition of the k-point set is simply not the same between these two calculations.
Read carefully the description of kptopt and kptbounds.