[Wien] WIEN2k 12 fft_modules

[Gavin Abo]

Dear Prof. Blaha,

Thanks, the scf cycle runs correctly using -O2 or -O3 with the new
files for the "fftpack" routines.  However, the scf cycle of the TiC
example does not converge with -O1 (in the lapw0 makefile) with wrong
values in TiC.output0 such as the plane wave contribution.  I don't
know whether the problem is reproducible on another system.

It seems to be due to "IMPLICIT REAL*8 (A-H,O-Z)" not being in the
PIMACH function at the end of the fortran file fftpack_helpers.f.
This line is in the function in the old file zfft3d.F.

Kind Regards,

Gavin

On Thu, Jul 26, 2012 at 1:42 AM, Peter Blaha
<pblaha at theochem.tuwien.ac.at> wrote:
> Thank's for the report.
>
> The problem concerns  lapw0, when compiled in sequential mode WITHOUT
> -DFFTW2 or -DFFTW3
> in the Makefile  (i.e. using the old "fftpack" routines instead of the new
> and faster fftw library).
>
> The fix suggested in the mail below does not work. Instead, you have to
> replace the 3 attached
> subroutines and recompile. (eramps.f, fft_modules.F fftpack_helpers.f)
>
> A corrected version is on the web.
>
> PB
>
>
> Am 25.07.2012 23:21, schrieb Gavin Abo:
>>
>> Dear Prof. Blaha,
>>
>> When I run the TiC example with WIEN2k 12 "without" k-point or mpi
>> parallelization, the program stops in lapw2 with the error shown below.
>> Here lapw2 cannot read the TiC.energy
>> file, because it is missing data in it as lapw0 gives bad output such as a
>> Density Integral with the value NaN in TiC.output0.
>>
>> The problem seems to be related to the new fft module.
>>
>> If lines 536-538 and 612-614 in SRC_lapw0/fft_modules.F:
>>
>> N2 = N+N
>> DO 117 I=1,N2
>>     C(I) = CH(I)
>>
>> are both changed to:
>>
>> DO 117 I=1,N
>>     C(I) = CH(I)
>>
>> Then, the error goes way.  On my system, N was the number 64.  The array C
>> had a size of 64, such that the loop is indexing outside the array (N2 =
>> 128).
>>
>> In Wien2k 11, TiC.output0 had:
>>
>> PLANE WAVE CONTRIBUTION -0.235589
>> :DEN  : DENSITY INTEGRAL  =          -754.35311720   (Ry)
>>
>> In Wien2k 12 with both changes made in fft_modules.F, TiC.output0 had:
>>
>> PLANE WAVE CONTRIBUTION -0.049778
>> :DEN  : DENSITY INTEGRAL  =          -753.97972930   (Ry)
>>
>> The density integral value is about the same, but the plane wave
>> contribution value may be significantly different.   So I'm not completely
>> sure if my change is correct.
>> Therefore, please let me know if a different change is needed.
>>
>> Thanks,
>>
>> Gavin
>>
>> forrtl: severe (59): list-directed I/O syntax error, unit 30, file
>> /home/gavin/wien/wiendata/TiC/TiC.energy
>> Image              PC                Routine Line        Source
>> lapw2              000000000053676A  Unknown Unknown  Unknown
>> lapw2              0000000000535266  Unknown Unknown  Unknown
>> lapw2              00000000004DFA30  Unknown Unknown  Unknown
>> lapw2              000000000049BDEF  Unknown Unknown  Unknown
>> lapw2              000000000049B2F7  Unknown Unknown  Unknown
>> lapw2              00000000004C10B3  Unknown Unknown  Unknown
>> lapw2              0000000000437F93  fermi_tetra_ 516  fermi_tmp_.F
>> lapw2              0000000000437423  fermi_ 111  fermi_tmp_.F
>> lapw2              00000000004721BA  MAIN__ 278  lapw2_tmp_.F
>> lapw2              0000000000403C9C  Unknown Unknown  Unknown
>> libc.so.6          00002B3BE2AF5C8D  Unknown Unknown  Unknown
>> lapw2              0000000000403B99  Unknown Unknown  Unknown
>>
> --
>
>                                       P.Blaha
> --------------------------------------------------------------------------
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-1-58801-165300             FAX: +43-1-58801-165982
> Email: blaha at theochem.tuwien.ac.at    WWW:
> http://info.tuwien.ac.at/theochem/
> --------------------------------------------------------------------------
>