The ABINIT Users Mailing List ( CLOSED )

[Emmanuel Arras <emmanuel.arras@cea.fr>]

Hi,
For your polarized system, use only 2 processors without  paral_kgb 1. If you don't have memory issues, it should be almost twice as fast.

Emmanuel



Zeila Zanolli a écrit :

87F04E45-A4A9-4613-8410-549579560E1A@uclouvain.be" type="cite">Dear all,

I'm trying my luck with the relaxation of a ~60 atoms molecule with abinit with PAW.

I've set-up a calculation in serial mode and one in parallel mode, using the band/fft parallelization.

However, the parallel calculation is taking the same time as the serial one, as you can see here:

serial:    63 broyden steps in 41 hours

7 cpus:  64 broyden steps in 40 hours

I've set the parallel flags using the paral_kgp = -n 

I have also have a spin-polarized system and in this case the parallel calculation was not proceeding at all:

the calculation stopped at the broyden step 0, after the 3^rd iteration.

The serial calculation for the same spin-pol system is, instead, proceeding without problems (ok - it is just extremely slow: 19 broyden steps in ~ 40 hours).

Here are my input files:

#--------------- for the parallel calculation ---------------------

paral_kgb 1

npkpt  1

npband 7       

npfft  1  

bandpp 4

nband 112

wfoptalg 4  nloalg 4  fftalg 401  intxc 0  fft_opt_lob 2

#-------------- the following is the same in the parallel and serial calculation ------

kptopt 1

ngkpt 1 1 1

nshiftk 1

shiftk 0 0 0

ntime 1000

tolmxf 1.e-5

ionmov 2

tolrff 1.e-2

ixc 1

ecut 20

pawecutdg 40

nstep 100

diemac 1

Same input for the spin-polarized case, just with the 'spin' variables in addition:

nsppol 2

and initialization of the spin.

Any help is appreciated!

Thanks,

    Zeila

---------------------------------------------------------------------------------------------

Dr. Zeila Zanolli

Université Catholique de Louvain (UCL)

Unité Physico-Chimie et de Physique des Matériaux (PCPM) 

Place Croix du Sud, 1 (Boltzmann)

B-1348 Louvain-la-Neuve, Belgium

Phone: +32 (0)10 47 3501 

Mobile: +32 (0)487 556699

Fax: +32 (0)10 47 3452

e-mail: zeila.zanolli@uclouvain.be

web: http://www.nano2hybrids.net/

---------------------------------------------------------------------------------------------

-- 
Emmanuel ARRAS
L_Sim (Laboratoire de Simulation Atomistique)
SP2M / INAC
CEA Grenoble
tel : 00 33 (0)4 387 86862