[Pw_forum] Yet another question about graphene bandstructure

[jbobak]

Hi Hadi,

Thank you for your quick response! I have tried that K-path also (I remain
confused as to whether K-paths are in real or reciprocal space, so I tried
both) with a similar result.

Julia

> Dear Julia,
>
> I guess your K-path is not entirely coincides with the high symmetry
> points for graphene. Make sure you span the following routes with enough
> K:
>
> 0	0	0
> 0.666	0.333	0
> 0.5	0.5	0
> 0	0	0
>
>
> HTH,
>
> Hadi.
> -----Original Message-----
> From: pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org] On
> Behalf Of jbobak
> Sent: 10 March 2014 17:04
> To: pw_forum at pwscf.org
> Subject: [Pw_forum] Yet another question about graphene bandstructure
>
> Hi all,
> I've searched the forum for this question, but nobody seems to be having
> quite the same issue, so I expect I'm doing something uniquely stupid. I
> am trying to calculate the band structure of graphene (using Espresso
> 5.0.3) for practice before I use a more complicated system. I do an SCF
> calculation with just the unit cell (2 atoms) with automatic k-points 18
> 18 1 0 0 0. Then I do a band structure calculation with k-points as
> follows:
>
> K_POINTS {tbipa}
> 7
> 0.00000 0.00000 0.00000 1
> 0.28868 0.16666 0.00000 1
> 0.57735 0.33333 0.00000 1
> 0.43301 0.41666 0.00000 1
> 0.28868 0.50000 0.00000 1
> 0.14435 0.25000 0.00000 1
> 0.00000 0.00000 0.00000 1
>
> I then run bands.x, followed by plotband.x which I run interactively.
> Everything works fine in that I get no errors, but the bandstructure plot
> is wrong (see attached pdf). The bands should cross at the K point. I
> think the problem has something to do with the k-points, which is why I
> have reproduced them above, but I have also attached the relevant input
> and output files. Could it be because the high-symmetry k-points I
> selected are not present in the automatically selected grid?
>
> Thank you so much for any help,
> Julia Bobak
>
> Research Assistant
> University of Victoria, Victoria, BC, CANADA
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>