[QE-users] Relax caculation not completed

[Leonid Kahle]

Hello Gui,

Another reason your calculation take very long is your low *mixing_beta* 
(ELECTRONS).
Is it really necessary? The smaller, the more robust, but the slower you 
get to the electronic ground state.
Also, your *conv_thr* (ELECTRONS) is quite high, it might lead to a lot 
of noise for the BFGS algorithm.
It's worth checking whether your forces have converged at that value, 
and if not, make it tighter. Here in the lab we typically use 1e-11*nat. 
It might make the overall time-to-solution for the ionic ground state 
faster, and your result will be much more accurate.

Hope it was helpful,

     Leonid



On 09/29/2018 05:43 AM, Gui Wei wrote:
> Hi,
> When I relax Fe(110)@Graphene system ( 2 iron layers, the bottom layer 
> is fixed and 1 graphene layer), It took about 3 days on 12 
> processors.And then I add a hydroxyl group and an epoxy group to the 
> graphene (GO),when I try to relax Fe(110)@GO system ,10 days have 
> passed,but the calculation has not completed.Is it a normal 
> phenomenon? Can I speed up the calculation by adjusting the 
> parameters?I put the latest structure in the attachment.
>
> &input
> &control
>     calculation  = 'relax',
>     prefix='relax919',
>     pseudo_dir = '/public/home/duan1/guiwei/QE/q-e-qe-6.3/pseudo/',
>     outdir='/public/home/duan1/guiwei/QE/q-e-qe-6.3/tempdir/'
>     tstress = .true.
>     tprnfor = .true.
>     etot_conv_thr=1.0D-4
>     forc_conv_thr=1.0D-3
> /
>  &system
>     ibrav= 0,
>     nat=127,
>     ntyp=4,
>     nspin = 2
>     starting_magnetization(1) =0.4
>     occupations='smearing',
>     smearing='mp',
>     degauss=0.02,
>     ecutwfc =46.0
>     ecutrho =240.0
>     vdw_corr='DFT-D'
>     london_s6 = 0.75
> /
> &electrons
>     conv_thr =  1.0d-5
>     mixing_beta = 0.1
>     mixing_mode = 'local-TF'
>     mixing_ndim=16
>     electron_maxstep=200
> /
> &IONS
>   ion_dynamics='bfgs'
> /
> CELL_PARAMETERS angstrom
>  19.67999  0.000000  0.000000
>  0.000000  8.521686  0.000000
>  0.000000  0.000000  17.00000
> ATOMIC_SPECIES
> Fe  55.847  Fe.pbe-n-kjpaw_psl.0.2.4.UPF
> C   12.0107  C.pbe-n-kjpaw_psl.0.1.UPF
> H   1.00   H.pbe-kjpaw.UPF
> O   16.00   O.pbe-kjpaw.UPF
> ATOMIC_POSITIONS  crystal
> ......
> K_POINTS automatic
> 2  2  1  0  0  0
>
> SCF cycles-energy
> 1-9767.89327
> 2-9768.09035
> 3-9768.21939
> 4-9768.29336
> 5-9768.3223
> 6-9768.34762
> 7-9768.35676
> 8-9768.36679
> 9-9768.37243
> 10-9768.37741
> 11-9768.38306
> 12-9768.38827
> 13-9768.39248
> 14-9768.39624
> 15-9768.39967
> 16-9768.40172
> 17-9768.40319
> 18-9768.40448
> 19-9768.40551
> 20-9768.40628
> 21-9768.40679
> 22-9768.4071
> 23-9768.40735
> 24-9768.40762
> 25-9768.40786
> 26-9768.4081
> 27-9768.40837
> 28-9768.40865
> 29-9768.409
> 30-9768.40946
> 31-9768.40995
> 32-9768.41052
> 33-9768.41119
> 34-9768.41209
> 35-9768.41307
> 36-9768.41367
> 37-9768.4144
> 38-9768.41472
> 39-9768.41506
> 40-9768.41546
> 41-9768.41586
> 42-9768.41613
> 43-9768.41647
> 44-9768.41681
> 45-9768.41705
> 46-9768.41728
> 47-9768.41754
> 48-9768.41781
>
>
> thanks
>
> Gui Wei
>
>
>
> _______________________________________________
> users mailing list
> users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20181002/47b36ee7/attachment.html>