[Pw_forum] (no subject)

[Prasenjit Ghosh]

ecutwfc determines the size of the plane wave you are using for your cal.
(Note that PWscf is a plane wave based code, i.e., the wave functions are
expanded in a plane wave basis).

If you use ultrasoft pseudopotential, you introduce augmentation charges
(because norm-conserving condition is not satisfied by these pp's). For
those one uses ecutrho.

In your case you are using norm-conserving pseudopotentials. Therefore for
ecutrho you can use the default value (ecutrho=4*ecutwfc). However, it is
better to use ultrasoft PP because you need lower value of ecutwfc, i.e.,
fewer no. of plane waves and therefore faster calculations.

There are plenty of good books & papers available. Please go through them
before you do the cal. or ask ur questions in the forum. Also look into the
manual & the mailing list archive.


Prasenjit.

PS: Don't forget to add ur affiliation.....its a netiquette for this forum.
2009/4/7 Dimpy Sharma <dimpy.sharma at tyndall.ie>

>
> Hi,
>
>  Can anyone please explain me the significance of ecutwfc and ecutrho in
> quantum espresso input file. And what is the diffeence between these two
> values.
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>


-- 
PRASENJIT GHOSH,
POST-DOC,
ROOM NO: 265, MAIN BUILDING,
CM SECTION, ICTP,
STRADA COSTERIA 11,
TRIESTE, 34104,
ITALY
PHONE: +39 040 2240 369 (O)
             +39 3807528672 (M)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20090407/4a3408ce/attachment.html>