Comment 19 for bug 1783785

Dear all,

yes, I expected this might be a problem, and this is why I made tests with
several basis sets. I understand that it is the f-pseudo the one that acts
on the f-polarization function, as there is not g-channel in the pseudos.

However, even if your answer would make sense, I do not think it is
definitive. A basis set with the g-character basis function worked
perfectly well until I included the third zeta function of d-character.
Before that, the polarization function of g-character caused no problems,
so I'm not sure that it is the one to blame.

In any case, the g-function is more important than the TZ d-function in
converging results. According to the review by Pykko on gold, it is well
established that basis functions of g-character are needed in other
localized basis codes. I found the same to be true in SIESTA if I want to
reproduce the benchmark results of plane-wave codes.

I will try to compile the trunk tarball that you mentioned in your
previous email, as I'm also interested in comparing on-site and off-site
results for gold (I believe that in gold S-O effects are important via an
"indirect" mechanism, namely the splitting of the d-orbitals modifies the
amount of s-d hybridization. Maybe the on-site formalism well captures
this effect). Have you tested if off-site calculations are significantly
more expensive than on-site ones?

Thanks again!

Andrés

On Thu, 16 Aug 2018, Roberto Robles wrote:

> Dear all,
>
> We have been looking at your input file and you are using a polarized
> shell of f electrons, meaning you have basis elements up to g character!
> Removing the f shell gives a correct behavior also with the onsite S-O.
>
> Roberto
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1783785
>
> Title:
> spin-polarized and spin-orbit calculations on a gold dimer crash
>
> Status in Siesta:
> New
>
> Bug description:
> Hi,
>
> I am using siesta-4.1-b3 version. I am calculating the gold dimer as a
> simple test of my pseudo and basis set. I have done all the main tests
> using a non-polarized calculation as Au_2 is obviously non-polarized.
> I found no problems at all. Then I wanted to see the effect of S-O
> coupling, but I first tried a spin-polarized calculation just as a
> sanity test. Both calculations (either spin-polarized or spin-orbit)
> proceed apparently well and the SCF convergence is reached. Just after
> that, when I guess the code prints out the final information (energy
> decomposition, dipole moment, etc) the code crashes, both in parallel
> and in serial (in serial I can read "Bus error"; in parallel not much
> information).
>
> I attach both the psf file with the pseudo and the fdf file below. I
> have checked that the mistake is only in the "Spin" order. If you set
> "Spin non-polarized" it works. If you just change this to "Spin
> polarized" it crashes.
>
> Any help will be appreciated. I'm not sure of this is a bug of a
> compiling problem, but the code compiled without any problem. And the
> spin-unpolarized calculation gives almost exactly the same result as
> 4.0.2 version, so it seems OK.
>
> Thanks in advance
>
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