# [Pw_forum] Problems with high ecutwfc for a C H As F S containing compound

Ludwig, Stephan stephan.ludwig at pi1.physik.uni-stuttgart.de
Thu Nov 12 10:19:17 CET 2015

```Hi,

I have the problem that I want to simulate an organic conductor.

I'm looking for convergence of the total energy with respect to the ecutwfc.

In the end I want to do optical investigations with the yambo program.

As a criterion for convergence I decided to choose a total energy difference of less than one meV per atom between two scf calculations.

ecutwfc	tot energy (Ry)	tot energy per atom (Ry)	tot energy per Atom in eV
80	-3173,1197	-13,4454224576	-182,9342903348
90	-3178,8757	-13,4698122881	-183,2661308812
100	-3183,225	-13,4882415254	-183,5168734262
120	-3189,049	-13,5129194915	-183,852634257
140	-3192,482	-13,5274661017	-184,0505509693
160	-3194,507	-13,5360466102	-184,1672947335
180	-3195,727	-13,5412161017	-184,2376292482
200	-3196,459	-13,5443177966	-184,279829957
220	-3197,176	-13,5473559322	-184,3211658972
240	-3197,176	-13,5473559322	-184,3211658972
260	-3197,34	-13,5480508475	-184,3306207008
280	-3197,446	-13,5485	-184,3367317324
300	-3197,501	-13,5487330508	-184,3399025507
320	-3197,5499	-13,5489402542	-184,3427216964

As you see I can't reach the convergence criterion.

As I understood the ecutwfc which is suitable depends on the used pseudopotentials.

I used these ones from the QE-database:

H 1.00790 H.pz-vbc.UPF
C 12.01100 C.pz-vbc.UPF
F 18.98800 F.pz-hgh.UPF
S 32.06500 S.pz-bhs.UPF
As 74.92200 As.pz-bhs.UPF

Does anybody knows which one causes the necessity of such a high ecutwfc?

Can anybody supply or suggest more suitable pseudos?

Thanks and regards

Stephan

The input file I use looks like this:

&CONTROL
title = 'etot_vs_ecutwfc' ,
calculation = 'scf' ,
max_seconds = 5.D+5,
restart_mode = 'from_scratch',
wf_collect = .TRUE.,
outdir = './' ,
wfcdir = './' ,
pseudo_dir = '/home/st/st_st/st_phy72394/pseudo/' ,
prefix = 'MeDH-TTPetot_vs_ecutwfc' ,
/
&SYSTEM
ibrav = -12,
A = 32.783 ,
B = 7.995 ,
C = 11.170 ,
cosAB = 0 ,
cosAC = -0.132602381688 ,
cosBC = 0 ,
nat = 236,
ntyp = 5,
ecutwfc = 280 ,
occupations = 'smearing' ,
degauss = 0.02 ,
force_symmorphic = .TRUE.,
smearing = 'gaussian' ,
exxdiv_treatment = 'gygi-baldereschi' ,
/
&ELECTRONS
conv_thr = 1.0D-8
/
ATOMIC_SPECIES
H 1.00790 H.pz-vbc.UPF
C 12.01100 C.pz-vbc.UPF
F 18.98800 F.pz-hgh.UPF
S 32.06500 S.pz-bhs.UPF
As 74.92200 As.pz-bhs.UPF
ATOMIC_POSITIONS angstroms
S 5.52835 0.29521 2.16999
S 21.91985 4.29246 2.16999
S 4.78777 7.69929 7.70567
S 21.17927 3.70204 7.70567
S 8.91117 6.37745 3.91040
S 25.30267 2.38020 3.91040
S 8.17058 1.61705 9.44608
S 24.56208 5.61430 9.44608
S 8.53628 0.30838 1.68728
S 24.92778 4.30563 1.68728
S 7.79569 7.68612 7.22296
S 24.18719 3.68887 7.22296
S 5.91488 6.35256 4.41083
S 22.30638 2.35531 4.41083
S 5.17429 1.64194 9.94651
S 21.56579 5.63919 9.94651
As 31.25307 7.42312 4.40640
As 14.86156 3.42587 4.40640
As 30.51248 0.57138 9.94208
As 14.12098 4.56863 9.94208
S 22.77175 0.24544 7.42335
S 6.38025 4.24269 7.42335
S 23.51233 7.74906 1.88767
S 7.12083 3.75181 1.88767
S 22.41272 6.31548 5.17143
S 6.02122 2.31823 5.17143
S 21.67213 1.67902 10.70711
S 5.28063 5.67627 10.70711
S 19.75130 0.27959 7.86510
S 3.35980 4.27684 7.86510
S 20.49188 7.71491 2.32941
S 4.10038 3.71766 2.32941
S 19.39879 6.33792 5.62425
S 3.00729 2.34067 5.62425
S 20.13937 1.65658 0.08857
S 3.74787 5.65383 0.08857
S 25.96310 0.08881 6.99046
S 9.57160 4.08606 6.99046
S 26.70368 7.90569 1.45478
S 10.31218 3.90844 1.45478
S 25.56056 6.28376 4.68983
S 9.16906 2.28651 4.68983
S 24.81997 1.71074 10.22551
S 8.42848 5.70799 10.22551
S 12.08748 6.57702 3.54505
S 28.47898 2.57977 3.54505
S 11.34689 1.41748 9.08073
S 27.73839 5.41473 9.08073
S 11.74373 0.68898 1.53781
S 28.13523 4.68623 1.53781
S 11.00315 7.30552 7.07349
S 27.39465 3.30827 7.07349
C 2.50124 7.97352 2.72134
C 18.89274 3.97627 2.72134
C 1.76066 0.02098 8.25702
C 18.15215 4.01823 8.25702
H 2.98979 0.63970 2.22534
H 19.38129 4.63695 2.22534
H 2.24920 7.35480 7.76102
H 18.64071 3.35755 7.76102
H 1.85588 0.41427 3.28266
H 18.24738 4.41152 3.28266
H 1.11530 7.58023 8.81834
H 17.50680 3.58298 8.81834
H 2.05231 7.38359 2.11352
H 18.44381 3.38634 2.11352
H 1.31173 0.61091 7.64920
H 17.70323 4.60816 7.64920
F 32.09159 6.20228 3.55280
F 15.70009 2.20503 3.55280
F 31.35101 1.79222 9.08848
F 14.95951 5.78947 9.08848
F 31.99917 0.61481 3.45094
F 15.60767 4.61206 3.45094
F 31.25859 7.37969 8.98662
F 14.86709 3.38244 8.98662
F 30.39326 0.65482 5.22458
F 14.00176 4.65207 5.22458
F 29.65268 7.33968 10.76026
F 13.26118 3.34243 10.76026
F 30.47339 6.23106 5.35854
F 14.08189 2.23381 5.35854
F 29.73280 1.76344 10.89422
F 13.34130 5.76069 10.89422
F 29.96030 7.30601 3.28598
F 13.56880 3.30876 3.28598
F 29.21972 0.68849 8.82166
F 12.82821 4.68574 8.82166
F -0.26088 7.52461 5.52461
F 16.13062 3.52736 5.52461
F -1.00147 0.46989 11.06029
F 15.39003 4.46714 11.06029
C 4.77264 7.25965 3.40666
C 21.16414 3.26240 3.40666
C 4.03205 0.73485 8.94234
C 20.42355 4.73210 8.94234
C 7.12868 7.79932 2.56191
C 23.52018 3.80207 2.56191
C 6.38809 0.19518 8.09759
C 22.77959 4.19243 8.09759
C 24.86295 7.22306 5.97079
C 8.47145 3.22581 5.97079
C 25.60353 0.77144 0.43510
C 9.21203 4.76869 0.43510
C 18.61690 7.45190 6.77235
C 2.22540 3.45465 6.77235
C 19.35749 0.54260 1.23667
C 2.96599 4.53985 1.23667
C 11.00638 7.55584 2.60731
C 27.39788 3.55859 2.60731
C 10.26580 0.43866 8.14299
C 26.65730 4.43591 8.14299
C 9.65436 7.44215 2.72245
C 26.04587 3.44490 2.72245
C 8.91378 0.55235 8.25813
C 25.30528 4.54960 8.25813
C 16.66566 0.56358 7.82192
C 0.27416 4.56083 7.82192
C 17.40624 7.43092 2.28624
C 1.01474 3.43367 2.28624
H 17.33387 0.90270 8.42088
H 0.94237 4.89995 8.42088
H 18.07446 7.09180 2.88520
H 1.68295 3.09455 2.88520
H 15.99844 0.08734 8.32234
H -0.39307 4.08459 8.32234
H 16.73902 7.90716 2.78666
H 0.34752 3.90991 2.78666
H 16.25380 1.29452 7.35581
H -0.13770 5.29177 7.35581
H 16.99438 6.69998 1.82013
H 0.60288 2.70273 1.82013
C 2.84149 6.31548 4.62008
C 19.23299 2.31823 4.62008
C 2.10091 1.67902 10.15576
C 18.49241 5.67627 10.15576
H 3.50975 5.72019 4.96440
H 19.90125 1.72294 4.96440
H 2.76917 2.27431 10.50008
H 19.16067 6.27156 10.50008
H 2.12009 5.80314 4.23922
H 18.51159 1.80589 4.23922
H 1.37951 2.19136 9.77491
H 17.77101 6.18861 9.77491
H 2.49999 6.86149 5.33308
H 18.89149 2.86424 5.33308
H 1.75941 1.13301 10.86876
H 18.15091 5.13026 10.86876
C 16.35379 6.90785 5.93536
C -0.03771 2.91060 5.93536
C 17.09438 1.08665 0.39968
C 0.70288 5.08390 0.39968
H 16.84589 6.32182 5.35300
H 0.45439 2.32457 5.35300
H 16.10531 1.67268 10.88868
H -0.28619 5.66993 10.88868
H 15.86389 7.54510 5.40947
H -0.52761 3.54785 5.40947
H 15.12331 0.44940 10.94515
H -1.26819 4.44665 10.94515
H 15.74245 6.39404 6.46678
H -0.64905 2.39679 6.46678
H 16.48303 1.60046 0.93110
H 0.09153 5.59771 0.93110
C 17.30660 7.62854 6.82992
C 0.91510 3.63129 6.82992
C 18.04719 0.36596 1.29424
C 1.65569 4.36321 1.29424
C 3.44486 7.19037 3.56498
C 19.83636 3.19312 3.56498
C 2.70427 0.80413 9.10066
C 19.09577 4.80138 9.10066
C 7.30907 6.93029 3.56166
C 23.70057 2.93304 3.56166
C 6.56849 1.06421 9.09734
C 22.95999 5.06146 9.09734
C 23.51465 7.25282 6.17782
C 7.12315 3.25557 6.17782
C 24.25523 0.74168 0.64214
C 7.86373 4.73893 0.64214
C 21.16001 7.74028 6.99710
C 4.76851 3.74303 6.99710
C 21.90060 0.25422 1.46142
C 5.50910 4.25147 1.46142
C 21.00252 6.87857 5.99071
C 4.61102 2.88132 5.99071
C 21.74310 1.11593 0.45503
C 5.35160 5.11318 0.45503
C 27.41664 7.76370 5.98186
C 11.02514 3.76645 5.98186
C 28.15722 0.23080 0.44618
C 11.76572 4.22805 0.44618
H 27.59489 0.54455 5.42718
H 11.20339 4.54180 5.42718
H 26.85431 7.44995 10.96286
H 10.46280 3.45270 10.96286
H 28.18126 7.63147 6.56310
H 11.78976 3.63422 6.56310
H 28.92184 0.36303 1.02742
H 12.53034 4.36028 1.02742
C 27.26323 6.60922 5.13933
C 10.87173 2.61197 5.13933
C 26.52265 1.38528 10.67501
C 10.13115 5.38253 10.67501
H 27.61795 5.83339 5.59879
H 11.22645 1.83614 5.59879
H 28.35854 2.16111 0.06311
H 11.96704 6.15836 0.06311
H 27.78169 6.73853 4.33001
H 11.39019 2.74128 4.33001
H 27.04111 1.25597 9.86569
H 10.64961 5.25322 9.86569
C 13.44202 0.18298 1.85556
C 29.83352 4.18023 1.85556
C 12.70144 7.81152 7.39124
C 29.09294 3.81427 7.39124
H 13.72839 7.55876 1.16581
H 30.11989 3.56151 1.16581
H 12.98780 0.43574 6.70150
H 29.37930 4.43299 6.70150
H 14.02273 0.95930 1.82235
H 30.41423 4.95655 1.82235
H 13.28214 7.03520 7.35803
H 29.67364 3.03795 7.35803
C 13.55775 7.53144 3.17416
C 29.94925 3.53419 3.17416
C 12.81716 0.46306 8.70984
C 29.20866 4.46031 8.70984
H 13.68661 0.21518 3.85616
H 30.07811 4.21243 3.85616
H 12.94602 7.77932 9.39184
H 29.33752 3.78207 9.39184
H 14.33307 6.94883 3.18191
H 30.72457 2.95158 3.18191
H 13.59248 1.04567 8.71759
H 29.98398 5.04292 8.71759
K_POINTS automatic
1 2 2 0 0 0

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