Why symmetry couldnt be deducted using ISYM

Message

muthukumar2k3 · #1 Post by **muthukumar2k3** » Wed Dec 16, 2009 3:40 pm

Dear Friends,

I am trying to set up a calculation using ISYM tag.

I expect Cs symmetry for my structure (Created by Material studio), but i am ending up with C1.

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The constrained configuration has the point symmetry C_1 .
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I attach my INCAR and POSCAR files as follows

-----------------------------------
INCAR
---
ISMEAR=0
SIGMA=0.01
NSW = 50
IBRION = 1
POTIM = 0.2
EDIFFG = -0.05
LWAVE=.FALSE.
LCHARG=.TRUE.
ISYM=1
SYMPREC=1e-4
------------------------------------

POSCAR
------------------------------------
Mo Te V O C H
1.000000000000000
20.0000000000000000 0.0000000000000000 0.0000000000000000
0.0000000000000000 20.0000000000000000 0.0000000000000000
0.0000000000000000 0.0000000000000000 23.0000000000000000
12 6 3 63 3 32
Selective dynamics
Cartesian
13.987185288 8.161699533 3.380065274 T T T
13.903818005 8.173882361 7.513722138 T T T
6.412204104 9.430777438 3.304451257 T T T
12.700068520 11.616075179 7.502306510 T T T
6.410169519 9.420943863 11.466731273 T T T
12.766252950 11.653027739 3.368486693 T T T
13.825707942 8.168704676 11.540751891 T T T
6.412746919 9.417161910 7.438943544 T T T
12.627397960 11.595342913 11.529387847 T T T
7.608479501 5.994305625 11.478095317 T T T
7.616496404 5.974969092 7.450359173 T T T
7.633136442 5.939449232 3.316029839 T T T
9.201591979 11.644568785 3.534191857 T T T
11.193762851 5.947838395 3.553084395 T T T
9.140330574 11.696728995 7.802842680 T T T
11.169500093 5.894198788 7.822086092 T T T
9.079023364 11.748478939 12.090276329 T T T
11.144906863 5.840962935 12.109867913 T T T
10.111123262 8.794706376 12.184111911 T T T
10.151059223 8.795397188 8.197409786 T T T
10.191570653 8.796097955 4.153260141 T T T
10.095131065 8.794429742 13.780570991 T T T
9.481439814 7.034109916 3.566203026 T T T
12.752751233 11.731066049 1.662215890 T T T
9.431042925 6.991084683 7.791812538 T T T
6.110070867 4.824155464 7.768099906 F F F
6.697250479 7.586125838 7.758888028 T T T
8.898376784 4.570119681 7.824020981 F F F
6.404768570 9.510937321 1.598241589 T T T
6.517182957 9.363606796 5.719746547 T T T
7.668364987 6.071733721 5.730663658 T T T
7.680816738 5.862002143 1.610342854 T T T
9.001547090 12.166431464 5.273627248 T T T
8.464369957 9.755343188 7.782645199 T T T
6.539001164 11.316893757 7.801646095 F F F
4.516785077 9.380250377 7.752990151 F F F
6.150264007 4.824850726 3.755724262 F F F
13.833842659 8.228033577 5.792798693 T T T
10.879049555 10.599847628 7.806980086 T T T
14.199822450 12.766773402 7.850574782 F F F
13.612955407 10.004808434 7.828583774 T T T
11.410954649 13.020799465 7.850745129 F F F
8.539365212 9.728027934 3.557268963 T T T
11.358924180 5.425372300 5.295983182 T T T
11.845722524 7.835589124 7.816147425 T T T
13.770330269 6.274025390 7.873120015 F F F
15.793108240 8.210678489 7.865684538 F F F
6.579200061 11.317589117 3.788695744 F F F
12.682660629 11.519906652 5.781881582 T T T
10.175244492 8.795815545 5.783057933 T T T
9.344227948 6.982760701 11.905342548 T T T
6.069876575 4.823460182 11.780590490 F F F
6.690735388 7.597860825 11.967339288 T T T
8.891640762 4.582056311 11.895854533 F F F
4.556978218 9.380945638 3.740614508 F F F
6.479471732 9.339626462 9.755802958 T T T
7.615552712 6.090935731 9.766576860 T T T
6.741053080 7.587453632 3.557399328 T T T
8.979608252 12.104714194 9.592355825 T T T
8.382751326 9.732159945 11.896224488 T T T
6.532722448 11.327522692 11.873483983 F F F
4.476590785 9.379555095 11.765480736 F F F
14.028799400 8.082130871 1.674317155 T T T
13.790693629 8.250615188 9.828809281 T T T
10.883442491 10.606745871 11.921426190 T T T
14.159628158 12.766078120 11.863065367 F F F
13.535163118 9.991615099 12.036316710 T T T
11.336120054 13.007451826 11.921892119 F F F
10.913312776 10.558286847 3.581193357 T T T
11.294343134 5.485592947 9.614307366 T T T
11.844919112 7.857346627 11.930544251 T T T
13.695038367 6.261985445 11.944262668 F F F
15.752913948 8.209983207 11.878175122 F F F
14.240015590 12.767468663 3.838199139 F F F
12.654612648 11.499305919 9.818035379 T T T
10.134608088 8.795112616 9.839683374 T T T
8.965398509 12.021791125 13.880063289 T T T
11.222655898 5.567030169 13.901469748 T T T
13.653328234 10.004936707 3.627060510 T T T
11.451153546 13.021494826 3.837794779 F F F
8.938575681 4.570815043 3.811070630 F F F
11.855387377 7.864368829 3.590127420 T T T
13.810529166 6.274720751 3.860169665 F F F
15.833301380 8.211373751 3.853308894 F F F
10.551607705 11.334596835 15.844112000 T T T
9.148357324 11.458748640 15.265110320 T T T
8.118173949 10.483533359 15.819588110 T T T
11.224920672 13.947469203 8.015965720 F F F
14.526884393 13.666864203 4.002172351 F F F
14.201987398 5.434370891 8.044198415 F F F
16.577613055 7.687054434 8.034377028 F F F
6.104000363 12.156490416 7.964357624 F F F
3.729056337 9.903818665 7.906133681 F F F
6.144194655 12.157185697 3.951867040 F F F
5.819978137 3.924704157 7.925962716 F F F
6.063801466 12.155795054 11.977307974 F F F
3.688856288 9.903123284 11.919198974 F F F
14.446491205 13.665473561 12.027613286 F F F
9.081067090 3.643392103 7.992590319 F F F
11.184721775 13.946773841 12.028916070 F F F
5.779778089 3.924008775 11.939028007 F F F
9.040868192 3.642696742 12.005540668 F F F
11.265114963 13.948164485 4.003475136 F F F
14.242181689 5.435066173 4.031707830 F F F
16.617806194 7.687749695 4.022001385 F F F
5.860171278 3.925399418 3.913587072 F F F
9.121261381 3.644087386 3.980099734 F F F
14.486691253 13.666168942 8.014547994 F F F
3.769249478 9.904513926 3.893758039 F F F
14.161788501 5.433675530 12.057148764 F F F
16.537413006 7.686359052 12.047442320 F F F
8.443671737 9.440392293 15.683601648 T T T
7.923444897 10.646990622 16.891108485 T T T
7.161191462 10.599620438 15.286890616 T T T
9.829262123 9.538232150 14.349460942 T T T
8.786951942 12.488305121 15.397150494 T T T
11.237063104 12.025106330 15.327966822 T T T
10.582753893 11.577051180 16.917908721 T T T
10.949624653 10.316818452 15.708856378 T T T
-----------------

Please help on how to make the calculation to run with symmetry.

Best regards,
Muthu

#2 Post by **admin** » Thu Dec 17, 2009 4:18 pm

please incease SYMPREC to the accuracy with which you give your coordinates in the input. If it still gives not the symmetry which you suppose your system has, please check if all positions are given coorectly