[Pw_forum] parallelization issue

Eyvaz Isaev eyvaz_isaev at yahoo.com
Fri Oct 15 11:35:34 CEST 2004


Dear Giacomo,

Please pay attention to your cell choice. You used 
ibrav=14, but with cosines = 0 and celldm(2,3)=1. So,
your system is cubic.

Bests,
Eyvaz.
 
--- Giacomo Saielli <giacomo.saielli at unipd.it> wrote:

> Dear developers,
> I wonder if the comments of paragraph 7.4 of
> espresso manual v 2.1, 
> parallelization issue of pw.x, apply also for the
> cp.x module.
> This is because I found the md simulations of my
> system with cp.x to be 
> not as fast as I need it.
> I have a system made of  242 atoms, 137 of which are
> protons, the rest 
> C, N, O. This is the relevant input section (I use
> Vanderbilt PPs):
> 
> &system
>  ibrav = 14,
> 
>     celldm(1) = 27.5945666, 
>     celldm(2) = 1.0, 
>     celldm(3) = 1.0, 
>     celldm(4) = 0.0, 
>     celldm(5) = 0.0, 
>     celldm(6) = 0.0, 
>     nat = 242,
>     ntyp = 4,
>     nbnd = 316,
>     nelec = 632,
>     ecutwfc = 30.0,
>     ecutrho = 180.0,
>     nr1b= 10, nr2b = 10, nr3b = 10,
>     xc_type = 'PBE',
>  /
>  &electrons
>     emass = 400.d0,
>     emass_cutoff = 2.5d0,
>     orthogonalization = 'ortho',
>     ortho_eps = 5.d-8,
>     ortho_max = 15,
>     electron_dynamics = 'verlet',
> !    electron_damping = 0.4,
> !    electron_velocities = 'zero',
>     electron_temperature = 'not_controlled',
>  /
>  &ions
>     ion_dynamics = 'verlet',
> !    ion_velocities = 'zero',
>     ion_temperature = 'nose',
>     fnosep = 60.0,
>     tempw = 300.0,
>  /
> 
> A test CPMD run with cp.x takes about 50 hours of
> total cpu (16 procs on IBM SP4 at CINECA, all PE of
> the same node) for 100 steps, that is about 15 fs
> (dt is 6 a.u. about 0.145 fs). This makes inpossible
> to run the simulation for some tens of picoseconds
> as I would like, since it would take something of
> the order of 10^5 cpu hours.
> 
> The question is if this numbers sounds correct to
> you, for this system size, so that the only chance
> is to build a smaller system, or if there is space
> for improvement playing with the choice of kpoints
> grid and other grids as mentioned in the Espresso
> manual,concerning pw.x. 
> 
> Here I attach the beginning of the output file
> 
> thank you very much
> best wishes
> Giacomo
> 
>
************************************************************************
> ****                                                
>                ****
> ****  CPV: variable-cell Car-Parrinello molecular
> dynamics          ****
> ****  using ultrasoft Vanderbilt pseudopotentials -
> v.2.1           ****
> ****                                                
>                ****
>
************************************************************************
> 
>      Parallel version (MPI)
>      Number of processors in use:     16
> Warning: card  &CELL ignored
> Warning: card     CELL_DYNAMICS = 'NONE', ignored
> Warning: card     CELL_VELOCITIES = 'ZERO', ignored
> Warning: card     PRESS = 0.0D0, ignored
> Warning: card     WMASS = 70000.0D0 ignored
> Warning: card  / ignored
> reading ppot for species #  1 from file
>
/scratch/padpdb42/saielli/PWSCF/TMA/CP/O.pbe-van_bm.UPF
> reading ppot for species #  2 from file
>
/scratch/padpdb42/saielli/PWSCF/TMA/CP/N.pbe-van_bm.UPF
> reading ppot for species #  3 from file
>
/scratch/padpdb42/saielli/PWSCF/TMA/CP/C.pbe-van_bm.UPF
> reading ppot for species #  4 from file
>
/scratch/padpdb42/saielli/PWSCF/TMA/CP/H.pbe-van_bm.UPF
>    wmass (calculated) =       233945.31
> 
> 
> 
>  nbeg=  1 nomore=    100    iprint=   2
>  reads from 51 writes on 51
>  time step =    6.0000
> 
>  parameters for electron dynamics:
>  emass=     400.00  emaec=       2.50ry
>  orthog. with lagrange multipliers: eps=  0.50E-07
> max= 15
>  verlet algorithm for electron dynamics
>  with friction frice =  0.0000 , grease =  1.0000
> 
> 
>  ions are allowed to move
>  ion dynamics with fricp =  0.0000 and greasp = 
> 1.0000
>  ion dynamics with nose` temp. control:
>  temperature required= 300.00000(kelvin) nose` mass
> =  16599.975
> 
> 
>  internal stress tensor calculated
>  cell parameters are not allowed to move
> 
> 
>  iprsta =  1
> 
>   unit vectors of full simulation cell
>  in real space:                         in
> reciprocal space:
>    27.5946    0.0000    0.0000              1.0000  
>  0.0000    0.0000
>     0.0000   27.5946    0.0000              0.0000  
>  1.0000    0.0000
>     0.0000    0.0000   27.5946              0.0000  
>  0.0000    1.0000
>  Proc  planes cols    G   planes cols    G   
> columns  G
>        (dense grid)     (smooth grid)   (wavefct
> grid)
>   1      8    680  53548    7    456  29172  114  
> 3634
>   2      8    680  53548    7    456  29172  114  
> 3634
>   3      8    680  53548    7    456  29172  114  
> 3630
>   4      8    680  53548    7    456  29152  114  
> 3630
>   5      8    681  53549    7    455  29151  113  
> 3629
>   6      8    680  53548    7    456  29168  114  
> 3630
>   7      8    682  53554    7    456  29132  114  
> 3630
>   8      8    682  53554    7    456  29132  114  
> 3630
>   9      7    682  53554    7    454  29126  112  
> 3628
>  10      7    682  53554    7    454  29118  112  
> 3628
>  11      7    682  53554    7    454  29126  112  
> 3628
>  12      7    682  53550    7    456  29160  116  
> 3632
>  13      7    682  53550    7    456  29148  112  
> 3628
>  14      7    682  53550    7    456  29156  112  
> 3628
>  15      7    682  53550    6    456  29168  112  
> 3628
>  16      7    682  53550    6    456  29164  114  
> 3630
>   0    120  10901 856809  110   7289 466417 1813 
> 58077
>  
>  ggen:  # of g vectors < gcut   ng=  26774
>  ggen:  # of g vectors < gcuts ngs=  14586
>  ggen:  # of g vectors < gcutw ngw=   1817
>  ggen:  # of g shells  < gcut  ngl=   2655
>  
>  
>  unit vectors of box grid cell
>  in real space:                         in
> reciprocal space:
>     2.2995    0.0000    0.0000              1.0000  
>  0.0000    0.0000
>     0.0000    2.2995    0.0000              0.0000  
>  1.0000    0.0000
>     0.0000    0.0000    2.2995              0.0000  
>  0.0000    1.0000
>  
>  ggenb: # of gb vectors < gcutb ngb =    243
>  ggenb: # of gb shells  < gcutb ngbl=     22
>  initialization 
> 
>  ibrav= 14 alat= 27.595 omega=21012.1616
>  gcut= 3471.84    gcuts= 2314.56 gcutw=  578.64
>  k-points: nkpt= 1
> 
>  meshes:
> 
=== message truncated ===



		
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