Energy is NaN with CUFFT

[Axel]

On Mar 14, 9:21 am, Ondrej Marsalek <ondrej.... at gmail.com> wrote:
> Hi,
>
> I have a problem with CUFFT. All seems fine except for a "small
> detail" - some energies in the output are NaN, zero, or infinity. The
> strange thing is that SCF seems to converge and reports sensible
> numbers in the "convergence" column. It looks like this:
>
>   ----------------------------------- OT --------------------------------------
>      1  OT DIIS        0.15E+00      9.652     0.0017576776                 NaN
>      2  OT DIIS        0.15E+00     12.499     0.0007020786                 NaN
>      3  OT DIIS        0.15E+00     12.474     0.0003829465                 NaN
>      4  OT DIIS        0.15E+00     12.426     0.0001190093                 NaN
>      5  OT DIIS        0.15E+00     12.452     0.0000853514                 NaN
>      6  OT DIIS        0.15E+00     12.439     0.0000527586                 NaN
>      7  OT DIIS        0.15E+00     12.459     0.0000396126                 NaN
>      8  OT DIIS        0.15E+00     12.452     0.0000282061                 NaN
>      9  OT DIIS        0.15E+00     12.470     0.0000229232                 NaN
>     10  OT DIIS        0.15E+00     12.483     0.0000185011                 NaN
>     11  OT DIIS        0.15E+00     12.494     0.0000153723                 NaN
>     12  OT DIIS        0.15E+00     12.462     0.0000133772                 NaN
>     13  OT DIIS        0.15E+00     12.462     0.0000115968                 NaN
>     14  OT DIIS        0.15E+00     12.515     0.0000104773                 NaN
>     15  OT DIIS        0.15E+00     12.479     0.0000093015                 NaN
>
>   *** SCF run converged in    15 steps ***
>
>   Total electronic density (r-space):          0.0000000000      256.0000000000

...and BTW. i would not call a total electronic density of 0.0 a
"sensible" number.
it looks as if the call to the fft in libcufft failed completely.

>   Total core charge density (r-space):       255.9999999917       -0.0000000083
>   Total charge density (r-space):                                255.9999999917
>   Total charge density (g-space):                                      Infinity

both _total_ charge densities have to sum up to the total charge of
the system (=0.0 here).

cheers,
    axel.
>
>   Overlap energy of the core charge distribution:              0.00000059138020
>   Self energy of the core charge distribution:             -1419.10895989560481
>   Core Hamiltonian energy:                                    84.83397930334846
>   Hartree energy:                                                           NaN
>   Exchange-correlation energy:                                 0.00000000000000
>   Dispersion energy:                                          -0.08192283398992
>
>   Total energy:                                                             NaN
>
>   outer SCF iter =    1 RMS gradient =   0.93E-05 energy =                  NaN
>   outer SCF loop converged in   1 iterations or   15 steps
>
>  ENERGY| Total FORCE_EVAL ( QS ) energy (a.u.):                              NaN
>
> Is it apparent what the problem is or should I just send in a testcase?
>
> Best,
> Ondrej