[Pw_forum] Help me with the Band Structure Calculation

[lan haiping]

On Mon, Feb 23, 2009 at 7:28 PM, Gabriele Sclauzero <sclauzer at sissa.it>wrote:

> Dear Hai-Ping,
>
> lan haiping wrote:
> > Hi , Gabriele,
> > Thanks for this emphasis.
> > I do wonder about any tricks to treat  DOS or
> > other nscf calculations with explicit kpoints set.
>
> What kind of tricks are you thinking of? I don't use any 'trick', but maybe
> there are.
> I usually do DOS/PDOS calculations starting from nscf k-point sets
> generated automatically
> (with or without offset, this should affect more or less convergency
> depending on the
> system, I think), so that weights are computed automatically and the
> hamiltonian is
> diagonlized only for points in the IBZ. In this way you can easily check
> convergence of
> the quantity you're interested in by simply increasing the grid size.

Thanks for sharing  your experience .  Due to
my laziness,  i havenot ever tried to use explicite kpoint sets but MP grids
to sample BZ .  This is why i do wonder about .


> > In fact , my previous works of nscf calculations on  DOS ,charge density
> > and electrostaic potential et al  were adopted  MP grids.
>
> What are MP grids? Do you mean Monkhorst Pack grids?

Yes, I do mean this scheme for BZ sampling.

>
> Maybe a more efficient way to converge faster DOS is to adopt the
> tetrahedra method, but
> I've never practiced with it (I don't know if it has been implemented for
> all cases, such
> as noncolinear, spin orbit, ...)
>

thanks again .


> GS
>
> >
> > Regards,
> >
> > On Mon, Feb 23, 2009 at 5:16 PM, Gabriele Sclauzero <sclauzer at sissa.it
> > <mailto:sclauzer at sissa.it>> wrote:
> >
> >
> >     lan haiping wrote:
> >      > Hi,  the weights of kpoints can be set to any value as decribed
> >     in the Doc.
> >
> >     You're right, but for this type of calculation only. Please be
> >     careful that's not the case
> >     in nscf calculations that will be used for DOS like calculations,
> >     for instance (maybe
> >     that's obvious, but I just wanted to point it out).
> >
> >     Regards,
> >
> >     GS
> >
> >      >
> >      > On Mon, Feb 23, 2009 at 3:21 PM, yccheng.nju
> >     <yccheng.nju at gmail.com <mailto:yccheng.nju at gmail.com>
> >      > <mailto:yccheng.nju at gmail.com <mailto:yccheng.nju at gmail.com>>>
> wrote:
> >      >
> >      >     You should set all number to "1" in the fourth column in
> kpoints.
> >      >     You have 311 K points, why you just give 5 in the input file.
> The
> >      >     error message have told you what your problem is !
> >      >
> >      >
> >     --
> >
> >
> >     o ------------------------------------------------ o
> >     | Gabriele Sclauzero, PhD Student                  |
> >     | c/o:   SISSA & CNR-INFM Democritos,              |
> >     |        via Beirut 2-4, 34014 Trieste (Italy)     |
> >     | email: sclauzer at sissa.it <mailto:sclauzer at sissa.it>
> >               |
> >     | phone: +39 040 3787 511                          |
> >     | skype: gurlonotturno                             |
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> >
> >
> >
> >
> > --
> > Hai-Ping Lan
> > Department of Electronics ,
> > Peking University , Bejing, 100871
> > lanhaiping at gmail.com <mailto:lanhaiping at gmail.com>, hplan at pku.edu.cn
> > <mailto:hplan at pku.edu.cn>
> >
> >
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>
>
> o ------------------------------------------------ o
> | Gabriele Sclauzero, PhD Student                  |
> | c/o:   SISSA & CNR-INFM Democritos,              |
> |        via Beirut 2-4, 34014 Trieste (Italy)     |
> | email: sclauzer at sissa.it                         |
> | phone: +39 040 3787 511                          |
> | skype: gurlonotturno                             |
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-- 
Hai-Ping Lan
Department of Electronics ,
Peking University , Bejing, 100871
lanhaiping at gmail.com, hplan at pku.edu.cn
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