Comment 10 for bug 1783785

hi again,

that solved the crash problem. Now the calculation finish properly.
Thanks!

The physical problem remains. The forces are unphysical. I have tried to
optimize the bond length, and as the atoms move in the direction of the
forces (to contract the bond) the forces get bigger and bigger. The
attached file "salida" is the output of this calculation, which I stopped
after five CG interactions as the calculation tends towards non-physical
too short distance, and the forces keep increasing. It seems a
catastrophic diverging behavior.

I have tested that my basis and pseudo reproduce, at the scalar
relativistic level, the reported benchmarks for the PBE functional, so the
pseudo and basis should be OK in principle. But the S-O results make not
physical sense yet...

I have read the instructions in //answers.launchpad.net/siesta/+faq/2779
and I hope to have followed them. I'm not sure if I should still compile
with debug options now that the computational problem has dissapeared.

I could try to perform S-O calculations in the bulk phase, or with smaller
basis sets to see what happens. Right now I have not better ideas. Let me
know if you have any other suggestions.

I'm about to depart with my family on summer vacations, so I will be 15
days out, I'm not in a hurry.

Thx a lot again!

Andrés

On Mon, 30 Jul 2018, Nick Papior wrote:

> Could you try and add this to your arch.make:
>
> state_analysis.o: state_analysis.F
> $(FC) -c $(FFLAGS_DEBUG) $(INCFLAGS) $(FPPFLAGS) $(FPPFLAGS_fixed_F) $<
>
> If you still have problems you should carefully follow the instructions
> here:
>
> https://answers.launchpad.net/siesta/+faq/2779
>
> such that we can use the debug options.
>
> --
> 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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