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
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/siesta/+bug/1783785/+subscriptions
>