The ABINIT Users Mailing List ( CLOSED )

[<zhouy6@rpi.edu>]

Hi Dear Fabien,

I just saw this email and felt quite curious about how you did that. because I
was trying to run GW calculation in parallel using both Abinit 5.4.3 and 
5.6.2.
There are only 12 atoms in my system. feels like it takes forever to generate
the KSS.

I remembered in one of your email you replied to the forum saying that you 
have
implemented the parallelisation in Abinit 5.6.x, but I didn't feel too much
improvement. I only see "treating xxx bands with npw=xxx for ikpt=1 by node 0"
or 1... in DFT part, but I didn't see the same output in the KSS step. Could
please you tell me what I have missed?
(the input file is at the end of this email: a 2D silicon surface band gap
calculation)

Thanks a lot for you help

Regards
Aaron


========================

For GW, my record is a system with 128 atoms running on 64 CPUs... But, the
answer depends strongly on the number of CPUs and amount of memory YOU have.
Bye.

Fabien

=========================

Zhiyong Zhang wrote:


    Dear All,


    I am a new potential user of ABINIT. To begin with I have a few general
questions: (1) how is the parallel efficiency of ABINIT? On a typical parallel
machine with fast connections such as IB, how many processors doe the code
scale up to? What would be the largest system the code can handle? (2) For the
GW calculation, what would be the largest system that the code can handle?


    Thank you very much in advance,

    Zhiyong

=======================

# First, a SCF density computation, then a non-SCF band structure calculation.

ndtset 4

#Dataset 1 : usual self-consistent calculation
kptopt1 1          # Option for the automatic generation of k points,
                   # taking into account the symmetry
nshiftk1 4
shiftk1  0.5 0.5 0.5  # These shifts will be the same for all grids
         0.5 0.0 0.0
         0.0 0.5 0.0
         0.0 0.0 0.5
ngkpt1  4 4 1
prtden1  1         # Print the density, for use by dataset 2

# Dataset2: calculation of kss file
# Definition of k-points
nshiftk2  4
nkpt2    80
shiftk2  0.0 0.0 0.0  # This grid contains the Gamma point
         0.0 0.5 0.0
         0.5 0.0 0.0
         0.5 0.5 0.0
istwfk2  80*1           # Option needed for Gamma
iscf2    -2             # Non self-consistent calculation
getden2  -1             # Read previous density file
nband2   24
nbandkss2 -1        # Number of bands to store in KSS file

# Dataset3: Calculation of the screening (epsilon^-1 matrix)
optdriver3  3        # Screening calculation
getkss3     -1       # Obtain KSS file from previous dataset
nband3      24      # Bands to be used in the screening calculation
ecutwfn3    3.6      # Planewaves to be used to represent the wavefunctions
ecuteps3    6.0      # Dimension of the screening matrix
ppmfrq3    16.7 eV  # Imaginary frequency where to calculate the screening

# Dataset4: Calculation of the Self-Energy matrix elements (GW corrections)
optdriver4  4        # Self-Energy calculation
getkss4     -2       # Obtain KSS file from dataset 1
getscr4     -1       # Obtain SCR file from previous dataset
nband4      24       # Bands to be used in the Self-Energy calculation
ecutwfn4    5.0      # Planewaves to be used to represent the wavefunctions
ecutsigx4    6.0      # Dimension of the G sum in Sigma_x
                     # (the dimension in Sigma_c is controlled by npweps)
nkptgw4      3                # number of k-point where to calculate the GW
correction
kptgw4                       # k-points
  0.500    0.000    0.000
  0.000    0.000    0.000
  0.000    0.500    0.000
bdgw4      18 19 18 19 18 19

#Definition of the unit cell
acell  7.680600    3.840300   12.3   angstrom
rprim  1.0 0.0 0.0
       0.0 1.0 0.0
       0.0 0.0 1.0

#Definition of the atom types
ntypat 2
znucl 14 1

#Definition of the atoms
natom 12          # There are two atoms
typat 6*1 6*2
xangst
0.80500000    0.00000000   15.76900100
3.03530000    0.00000000   15.76900100
0.07500000    1.92015000   14.79425100
3.76530000    1.92015000   14.79425100
1.92015000    1.92015000   13.36150100
5.76532091    1.92015000   13.57954266
5.88860833    3.18376131   12.83860631
5.76382098    0.79532825   12.63314222
1.92015000    3.12818098   12.52390852
1.92015000    0.71211902   12.52390852
0.80500000    0.00000000   17.189
3.03530000    0.00000000   17.189

#Definition of the planewave basis set
ecut 12.0

# Use only symmorphic operations
symmorphi 0

# Definition of the SCF procedure
nstep   10
diemac  12.0
tolwfr  1.0d-10
prtvol   3        # print out all k-points