[Pw_forum] convergence problem

[H.Y. Geoffrey Tse]

Providing the structure built is correct, then your energy cutoff set is too low.

I would suggest, go for something like ecutwfc = 80; ecutrho = 4*ecutwfc

 

Geoffrey

 

From: pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org] On Behalf Of Pallavi Bothra
Sent: 2014年6月27日 下午 06:09
To: pw_forum at pwscf.org
Subject: [Pw_forum] convergence problem

 

Dear all,

              I am trying to do a scf calculation considering spin-orbit interaction. Here is the input file:

&CONTROL
    calculation = 'scf',
    restart_mode='from_scratch',
    prefix='BiTe',
    pseudo_dir = './',
    outdir='./tempc',
    nstep = 500
 /
 &system
    ibrav=  0,
    nat= 40,
    ntyp= 2,
    celldm(1) = 1.890359168,
    ecutwfc = 30.0,
    ecutrho= 300.0,
    occupations='smearing',
       degauss = 0.01 ,
     smearing = 'cold' ,
     starting_magnetization(1) = 0.5
     starting_magnetization(2) = 0.5
           noncolin = .true.
             lspinorb = .true.
              
/
 &ELECTRONS
              electron_maxstep = 500 ,
                 conv_thr = 1.0d-10
                 mixing_beta = 0.1 ,
               mixing_mode = 'local-TF',
               mixing_ndim = 10 ,
/
 &IONS
               upscale = 100 ,


/

CELL_PARAMETERS
8.7900000    0.00000000    0.00000000
-4.3950000   7.6123633    0.00000000
0.00000000    0.00000000    36.64000000

ATOMIC_SPECIES
Te   127.6     Te.rel-pbe-dn-rrkjus_psl.0.2.2.UPF
Bi   208.980   Bi.pbe-d-mt.UPF

ATOMIC_POSITIONS angstrom
Te       0.001076915  -0.001111167  24.534365287
Bi       0.000000000   0.000000000  12.190002400    0   0   0
Te       2.197500000   1.268727220  10.146666670    0   0   0
Te      -0.001767560   2.537644595  20.687693846
Te       0.000000000   0.000000000   6.383268000    0   0   0
Te       2.197537577   1.265453382  16.833926576
Te      -0.000000000   2.537454430  13.910065330    0   0   0
----------------------------
K_POINTS automatic
4 4 1   0 0 0

Actually first I have relaxed the structure w/o considering spin-orbit interaction. Then I used the optimised coordinates to do the scf calculation but the system did not converge even after 300 cycles.

Thank you in advance

Regards

Pallavi Bothra

JNCASR, Bangalore

India

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20140627/bcc81f14/attachment.html>