[gpaw-users] LCAO basis sets generation

[Alexander Romanov]

Dear, Ask

Thanks a lot for your help. Now I can make my calculation with PW91
functional (and other
functionals too).

Concerning inaccurate results: Previously I saw strange shifts of different
parts of optimization
curve during lattice constant searching.  I made some calculations with
default dzp basis
sets and often couldn't converged shifts at all.

After generation proper dzp and tzp basis sets for functionals most of
these shifts have disappeared. I play two days around this problem and it
seems to me that I can overcome
it now. I still have found shifts in some places but now they can be
converged by slightly
increasing accuracy of solving Poisson equation or grid space.

I am a little bit surprised why these shifts move only part of the curve
far from the minimum.
May be it's a consequence of finite "rcut"?

Best regards,
Alex




2016-03-23 18:44 GMT+03:00 Ask Hjorth Larsen <asklarsen at gmail.com>:

> (Re-added list; please reply to list)
>
> 2016-03-23 9:40 GMT+01:00 Alexander Romanov <alphard.rm at gmail.com>:
> > Thanks for your  reply, Ask.
> >
> > I have found the source of discrepancy between command line and script
> > generation. Command line gpaw-basis has a parameter scalarrel = True as a
> > default one. Now I have only little difference in basis sets.
> >
> > But I still can not use PW91 basis set in my calculation. When I do
> > something like this:
> >
> > calc = GPAW(mode='lcao', basis='dzp', xc='PW91', kpts=(12,12,12,),
> > txt=Pt_Lconst.txt)
> >
> > I get an error:
> >
> > RuntimeError: Could not find required PAW dataset file "Pt.PW91".
> >
> > I has no error with other xc (LDA, PBE, RPBE).
> >
> > So, the question is: can I do calculation with PW91 functional in lcao
> mode?
>
> You need to generate a PW91 setup.  gpaw-basis does not save it,
> although for technical reason it is calculated as part of the
> calculation.  So either run gpaw-setup <....> and later gpaw-basis
> with corresponding parameters, or write a script which generates both
> the setup and its corresponding basis set and saves them.
>
> It has been on my stagnant todo-list for years to do allow to save the
> setup file while running gpaw-basis (and many other improvements).
>
> Now *drumroll* there's a merge request which will implement this:
>
>   https://gitlab.com/gpaw/gpaw/merge_requests/27
>
> Then this will be possible:
>
>   gpaw-basis --save-setup <args>
>
> You mentioned that some results were inaccurate.  Could you please
> elaborate?
>
> Best regards
> Ask
>
>
> >
> > Best regards,
> > Alex
> >
> >
> > 2016-03-22 17:00 GMT+03:00 Ask Hjorth Larsen <asklarsen at gmail.com>:
> >>
> >> Dear Александр
> >>
> >> 2016-03-22 13:05 GMT+01:00 Александр Романов <alphard.rm at gmail.com>:
> >> > Hello,
> >> >
> >> > We've use LCAO mode for fast optimization and met some problems with
> >> > basis
> >> > sets
> >> > for transition metals.
> >> >
> >> > Default dzp basis sets for Cu, Ag, Pd and Pt give unphysical results
> for
> >> > lattice constant.
> >>
> >> Which lattice constant do you get then, and which did you expect?
> >> Would you please attach the input scripts and logs?
> >>
> >> > Better convergence of Poisson solver, denser k-points and grid-points
> >> > meshes
> >> > give no improvement.
> >> > We've tried to use gpaw-basis command and manual script for making tzp
> >> > sets.
> >> > So, we have
> >> > two questions:
> >> >
> >> > 1)If we use command
> >> >
> >> > gpaw-basis -f PW91 --lpol=1 -t tzp Pt
> >> >
> >> > we get an error:
> >> >
> >> > File "/home/user/bin/gpaw-1.0.0/lib/python/gpaw/atom/all_electron.py"
> .
> >> > line
> >> > 779. in shoot
> >> > dudrplus = 0.5 * (u[gtp + 1] - u[gtp - 1]) / dr[gtp]
> >> > IndexError: index out of bounds
> >> >
> >> > But all works fine for PBE and RPBE functionals or other elements (for
> >> > example, Pd).
> >> >
> >> > 2) If we use manual script, we get basis set twice as large as
> >> > gpaw-basis
> >> > set. As a consequence we've got
> >> > slow calculations.
> >>
> >> Again, please attach the script.
> >>
> >> >
> >> > How can we resolve problem with gpaw-basis command and what's the
> >> > difference
> >> > between gpaw-basis
> >> > and manual script basis set generation?
> >>
> >> gpaw-basis is a limited interface.  If you write a Python script to
> >> generate the basis, you get much more flexibility.  This may in the
> >> end be what you are looking after, if gpaw-basis does not serve.
> >>
> >> Best regards
> >> Ask
> >>
> >> >
> >> > Best regards,
> >> >
> >> > Alex
> >> >
> >> >
> >> >
> >> >
> >> > _______________________________________________
> >> > gpaw-users mailing list
> >> > gpaw-users at listserv.fysik.dtu.dk
> >> > https://listserv.fysik.dtu.dk/mailman/listinfo/gpaw-users
> >
> >
>
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