[Pw_forum] Difference between "bands" and "nscf" calculations

[Paolo Giannozzi]

On Wed, 2013-12-11 at 17:14 +0100, H. Lee wrote:

> Then, can I understand that except for the calculation of the Fermi
> level and occupation numbers, there is little difference between
> "bands" and "nscf" modes?

also the way symmetry is treated is different. 'bands' accepts whatever
list of k-points, 'nscf' always produces a symmetry-adapted grid.

P.

> 
> 
> Regards.
> 
> 
> On Wed, Dec 11, 2013 at 4:34 PM, Paolo Giannozzi
> <paolo.giannozzi at uniud.it> wrote:
>         I have explained the difference between 'nscf' and 'bands'
>         a few days ago
>         
>         P.
>         
>         On Wed, 2013-12-11 at 14:00 +0100, H. Lee wrote:
>         > Dear all:
>         >
>         >
>         > I have a question on the difference between "bands" and
>         "nscf"
>         > calculations.
>         >
>         >
>         > Reading the manuals and readings in this forum, I know that
>         >
>         >
>         > (1) they are all one-step non-self-consistent calculations
>         with use
>         > and fix of the charge density obtained in the previous "scf"
>         > calculations
>         >
>         > (2) "nscf" calculation is used for calculation of dos and in
>         this
>         > "nscf" mode, unlike "bands" mode, the Fermi level and
>         occupation
>         > numbers are calculated.
>         >
>         >
>         > But, I can't still understand clearly the difference between
>         these two
>         > modes.
>         >
>         > I think that all types of calculations performed in "bands"
>         mode, for
>         > example bands calculation, can be performed in "nscf" mode,
>         too. Is it
>         > right?
>         >
>         >
>         > In addition, I would like to know the case for which only
>         "nscf" mode
>         > should be performed, except for the calculation of dos.
>         >
>         >
>         >
>         > Regards,
>         >
>         
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>         
>         
>         --
>          Paolo Giannozzi, Dept. Chemistry&Physics&Environment,
>          Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
>          Phone +39-0432-558216, fax +39-0432-558222
>         
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> 
> 
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-- 
Paolo Giannozzi, Dept. Chemistry&Physics&Environment, 
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222