[Pw_forum] Can't get converged results when using ESM method

Xin Li xinli at lbl.gov
Thu Sep 20 16:22:48 CEST 2012


 Dear all,

I meet a big problem when doing ESM calculations that all the calculations
couldn't get converged.
The input is posted below and the efforts I made are,

1, using different degauss
2, using different ecutwfc
3, using different esm_bc
4, using different number of cores
5, using different tot_charge
6, searching on the pw_forum

It can be converged when tot_charge=0. But otherwise, it can't and just run
out of all the steps. The strange thing is the total energies in each step
vary quite differently.
For example,
at step #47, the total energy is -7776.16619281 Ry,
at step #52, the total energy is -5612.51355642 Ry,
but step #53, the total energy is -8825.13517388 Ry.
just doesn't have trend to converge.

For esm_bc, pbc and bc1 were tested, but none of them worked.

Hope you can help me out of this issue.
Thanks a lot.

Best,
Xin
LBNL, CA

##############INPUT, pw.in###################
&control
    calculation='scf'
    prefix='HOPG'
    pseudo_dir='/'
    outdir='./'
    wf_collect=.TRUE.
    disk_io='low'
    restart_mode='from_scratch'

/
&system
    ibrav=8 , a=4.2384 , b=2.447 , c=32.0875
    nat=16, ntyp=1, tot_charge=-2
    nbnd=96, occupations='smearing', degauss=0.0019
    ecutwfc=35, ecutrho=300
    assume_isolated = 'esm', esm_bc='bc1'
/
&electrons
    electron_maxstep=300
    conv_thr=1.0d-7
    mixing_mode='local-TF'
    mixing_beta=0.1

/
ATOMIC_SPECIES
C 12.00 C.pbe-van_bm.UPF
ATOMIC_POSITIONS angstrom
C      0.000000000    1.223500013   11.521874905
C      1.412785889    1.223500013   11.521874905
C      2.119199991    0.000000000   11.521874905
C      3.531985754    0.000000000   11.521874905
C      0.000000000    1.223500013   14.834999979
C      0.706414102    0.000000000   14.834999979
C      2.119199991    0.000000000   14.834999979
C      2.825614220    1.223500013   14.834999979
C      0.000000000    1.223500013   18.148125053
C      1.412785889    1.223500013   18.148125053
C      2.119199991    0.000000000   18.148125053
C      3.531985754    0.000000000   18.148125053
C      0.000000000    1.223500013   21.461249470
C      0.706414102    0.000000000   21.461249470
C      2.119199991    0.000000000   21.461249470
C      2.825614220    1.223500013   21.461249470
K_POINTS automatic
 17 31 1 0 0 0
##############################################
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