The ABINIT Users Mailing List ( CLOSED )

["Nuno A. G. Bandeira" <nuno.bandeira@ist.utl.pt>]

lichenliang1980@yahoo.com.cn wrote:

> Hello,
> Thanks for your help.
> I am trying to calculate the band structure using PAW in Abinit.I think that  
> computing band structures with kpoints generated automatically with a 
> Monkhorst-Pack grid are a very rough plot. Can I calculate the band structure 
> with input specification using PAW in abinit?
> Thanks
> Li

There's no problem doing that all you have to do is this

nkpt 30
kpt
0.0 0.0 0.0
...
0.5 0.5 0.5

if you specify 30 kpoints the program expects 30 entries in kpt in 
natural coordinates - (0.0,0.0,0.0) being the zone centre and 
(0.5,0.5,0.5) being the edge or (pi/a,pi/b,pi/c). In between these two 
you have to input the rest of the kpoints and, if needs be, specify 
their weight with wtk.

The important k points will depend on the size and shape of your unit 
cell. There's an extended Hückel program called Yaehmop that carries 
some nice utilities that give you kpoint sets for some common unit 
cells. That might help.

On the other hand I don't see why MP grids won't suffice. If you're not 
happy with the default values all you need to do is specify

ngkpt 10 10 10

or even higher to produce results automatically with no fuss.

But I'm sure you have your reasons...


Regards,

--
Nuno A. G. Bandeira, AMRSC
Graduate researcher and molecular sculptor
Inorganic and Theoretical Chemistry Group,
Faculty of Science
University of Lisbon - C8 building, Campo Grande,
1749-016 Lisbon,Portugal
http://cqb.fc.ul.pt/intheochem/nuno.html
Doctoral student @ IST,Lisbon
--