The ABINIT Users Mailing List ( CLOSED )

[gilles zerah <gilles.zerah@wanadoo.fr>]

Also, the chkexit flag might lead to waiting procs--Gilles
> Dear Gilles,
>
> Here is the input file I have been using:
>
> ---------------------------------------------------------------------------------------------------------------------------- 
>
> #Definition of the unit cell
> acell 13.1493536801862057 15.1976493759670106 14.3247149284289197 
> angstrom
>
> #Definition of the planewave basis set
> ecut   850 eV # Maximal kinetic energy cut-off, eV
>
>
> #Definition of k-points
> nkpt 1    
> #Definition of the SCF/Ionic relaxation procedure
> ionmov  3           # Use the modified Broyden algorithm
> ntime  1000         # Maximum number of Broyden "timesteps"
> tolmxf 1.d-3       # Stopping criterion for the geometry optimization 
> : when
>                     # the residual forces are less than tolmxf, the 
> Broyden
>                     # algorithm can stop. The maximum force should be 
> less than 0.015 eV/A
> toldff 1.0d-4       # Will stop the SCF cycle when, twice in a row,
>                     # the difference between two consecutive 
> evaluations of
>                     # forces differ by less than toldff (in Hartree/Bohr)
>
>
>
> #Parallelization specifications
> npband 16 npfft 1
> timopt -1
> fftalg 401
> nloalg=4
> wfoptalg 4
> fft_opt_lob 2
> iprcch 0
> intxc 0
> istwfk 1 #Do not take advantage of time-reversal symmetry
>
> #Exchange-correlation functional
> ixc=11            #PBE
>
> #Electron bands
> nband 400  
> #Output options
> enunit 2    #Print energies in Hartrees and eV
> prtden 1
> prtwf 1
> prtgeo 1
> chkexit 1 #Check for soft exit
>
> #Definition of the atoms
> natom  288
> ntypat 2
> typat  96*2 192*1
> znucl  1 8
> xred
>  0.0845189269132292  0.0836540240171464  0.0938979747640865
>  0.2509028928683434  0.1665132426871575  0.1569498160978585
>  0.0832245541612382  0.0833713592505196  0.4056550678678152
>  0.2499432940905800  0.1673060143511642  0.3441180505891231
>  0.2505816959654373  0.3327266212961689  0.0944438710086825
>  0.0832112596230180  0.4163646775571404  0.1555981974101562
>
> .....
>
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ 
>
>
>
> gilles zerah wrote:
> > Dear Maurice,
> >
> > The best distribution of npbands and npfft depends presumably upon 
> > the implementation of MPI you are using and of many
> > other parameters. Now, it should work for this distribution, but the 
> > case npfft=1 is treated differently.
> > Is it possible you post your input file?
> >
> > Gilles
> > > Dear all,
> > >
> > > I noticed strange behavior while using the bands/fft parallelization 
> > > features of abinip (compiled with -DMPI_FFT preprocessor flag),
> > > running on an SGI Altix system with 16 CPU´s.
> > >
> > > The calculation in question involves a geometry optimization using 
> > > only the gamma point:
> > >
> > > 1) The first calculation was run using the parameters:
> > >
> > > npbands=8, npfft=2
> > >
> > > This calculation runs fine and the geometry optimization converges 
> > > without any trouble.
> > >
> > > 2) Then I tried a different distribution, using the parameters
> > >
> > > npbands=16, npfft=1
> > >
> > > According to the documentation, this should be more efficient than 
> > > the first choice.
> > >
> > > But while running this calculation something strange happens. After 
> > > a while, only a few
> > > of the 16 CPU´s are actually processing, with the remainder in 
> > > "uninterruptable sleep".
> > > This already occurs during the first SCF cycle, effectively 
> > > interrupting the progress of
> > > the calculation.
> > >
> > > Any ideas?
> > >
> > > Cheers,
> > >
> > > Maurice