[gpaw-users] gpaw setup generation

[Marcin Dulak]

Hi,

please have a look at 
https://listserv.fysik.dtu.dk/pipermail/gpaw-users/2011-March/000737.html
The parameters for Hf are reported there, and the question of electronic 
core/valence configuration addressed there.
Please try first to use that one, test it and report any problems.
Note that simple bulk results will be probably OK, it's when combining 
with other elements (like O, N, ..) where setups sometimes fail.
Please contact Ulrik - he is also testing Hf currently (continuing 
discussion on gpaw-users).

Best regards,

Marcin

Ville Mäkinen wrote:
> Dear GPAW users,
>
> we are interested in performing GPAW calculations with Hafnium. 
> Currently there are no ready setups for this element so we decided to 
> try to generate it ourselves. There are some questions that we could 
> not find answers from the gpaw wiki page.
>
> 1. The electronic configuration of Hafnium is [Xe],4f14,5d2,6s2. Is 
> there any way to say whether the 4f-electrons should be included in 
> the valence states or not?
>
> 2. We generated the setup with both 4 and 18 valence electrons. Trying 
> to perform an actual GPAW calculation with 18-valence -version raises 
> an exception
>
> ...
>     T_Lqp = self.calculate_T_Lqp(lcut, nq, _np, nj, jlL_i)
> File 
> "/fs/local/linux26_x86_64/appl/nano/gpaw/0.6/lib/python/gpaw/setup.py", 
> line 804, in
>  calculate_T_Lqp
>     T_Lqp[:, q, p] = G_LLL[L1, L2, :Lcut]
> ValueError: shape mismatch: objects cannot be broadcast to a single shape
>
> This happens at least with gpaw version 0.6.5150 and svn-version 
> 0.8.0.7944. Do you think this is a bug or is there some upper limit 
> for the number of valence electrons?
>
> 3. Choosing the cutting radii for the valence states is a bit unclear. 
> On some elements the different orbitals have very different radii 
> whereas on some others they are all the same. Is there any rule of 
> thumb how to choose them, or simply by trial and error?
i would say trial and error.
>
> 4. One question concerning the convergence tests. The spin-paired 
> isolated atom energy approaches zero as h -> 0, but why does the dimer 
> energy behave in the same way? My first thought was that it should 
> converge to the "real" dimer bonding energy instead.
when calculating a dimer you need to make sure that you have the right 
electronic state, no fractional occupancies (set width=0), the box is 
large enough; the same holds for the isolated atom.
You need also accurate reference DFT results to compare to.
>
> Best regards
> ----------------------------------------------
> Ville Mäkinen
> ville.p.makinen at jyu.fi <mailto:ville.p.makinen at jyu.fi>
> PhD student,
> University of Jyväskylä, Department of Physics
> ----------------------------------------------
> ------------------------------------------------------------------------
>
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-- 
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Marcin Dulak
Technical University of Denmark
Department of Physics
Building 307, Room 229
DK-2800 Kongens Lyngby
Denmark
Tel.: (+45) 4525 3157
Fax.: (+45) 4593 2399
email: Marcin.Dulak at fysik.dtu.dk

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