please vary the % of change or volume -10,-5.0,5,10 like this.If your systeem is optimised one i think lattice constants will not change too much..<br><br>
<div class="gmail_quote">On Wed, Jul 9, 2008 at 6:25 PM, zhs064 <<a href="mailto:zhs064@mail.usask.ca">zhs064@mail.usask.ca</a>> wrote:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Dear Wien2k users,<br><br> I'm working on Ca_cmca (space group is 64) at high pressure. I got<br>all cell constants<br>
and atomic positions from the optimized values generated by the other<br>program. The initial structure file looks like:<br>**************************************************************<br>Title Ca cmca<br>CXY 1<br>
MODE OF CALC=RELA<br> 8.435170 8.861303 8.446130 90.000000 90.000000 90.000000<br>ATOM -1: X=0.00000000 Y=0.34493000 Z=0.19252000<br> MULT= 4 ISPLIT=<br> -1: X=0.00000000 Y=0.15507000 Z=0.69252000<br>
-1: X=0.00000000 Y=0.84493000 Z=0.30748000<br> -1: X=0.00000000 Y=0.65507000 Z=0.80748000<br>Calcium NPT= 781 R0=.000500000 RMT= Z: 20.0<br>LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000<br> 0.0000000 1.0000000 0.0000000<br>
0.0000000 0.0000000 1.0000000<br> 0<br>***************************************************************<br>I wanna do the optimization on both cell constants and atomic positions<br>with constant<br>volumes. The question is I found the optimized cell constants don't<br>
change and the atomic positions changed<br>very small (< 0.001), I think these results doesn't make sense. Anybody<br>can tell me some ideas about them?<br>What I did is the following commands:<br>-- instgen_lapw<br>
-- init_lapw (I used PBE -6.0 Ry )<br>-- run_lapw (scf)<br>-- x optimize (actually in this step, I chose "[3] VARY C/A RATIO with<br>CONSTANT VOLUME and B/A (orthorh lattice)"<br> at -4,-2,0,2,4, then at each C/A variation I run "x optimize" again<br>
to get 5 B/A variations and renamed them, i.e. chose<br> "[4] VARY B/A RATIO with CONSTANT VOLUME and C/A (orthorh lattice)",<br>finally I got 25 structure files)<br>-- I changed the script " optimize.job ", see below.<br>
****************************************************<br>#!/bin/csh -f<br> # Modify this script according to your needs:<br> # Uncomment one of the lines ...<br> # Change run_lapw to runsp_lapw or use different convergence criterium<br>
# Change save_lapw -d XXX<br>foreach i ( \<br> Ca_cmca_1_5_boa___0.0_0 \<br> Ca_cmca_1_5_boa___0.0_-4 \<br> Ca_cmca_1_5_boa__-4.0_-4 \<br>
Ca_cmca_1_5_boa__-2.0_-4 \<br> Ca_cmca_1_5_boa___2.0_-4 \<br> Ca_cmca_1_5_boa___4.0_-4 \<br> Ca_cmca_1_5_boa__-4.0_-2 \<br>
Ca_cmca_1_5_boa__-2.0_-2 \<br> Ca_cmca_1_5_boa___0.0_-2 \<br> Ca_cmca_1_5_boa___2.0_-2 \<br> Ca_cmca_1_5_boa___4.0_-2 \<br>
Ca_cmca_1_5_boa__-4.0_0 \<br> Ca_cmca_1_5_boa__-2.0_0 \<br> Ca_cmca_1_5_boa___2.0_0 \<br> Ca_cmca_1_5_boa___4.0_0 \<br>
Ca_cmca_1_5_boa__-4.0_2 \<br> Ca_cmca_1_5_boa__-2.0_2 \<br> Ca_cmca_1_5_boa___0.0_2 \<br> Ca_cmca_1_5_boa___2.0_2 \<br>
Ca_cmca_1_5_boa___4.0_2 \<br> Ca_cmca_1_5_boa__-4.0_4 \<br> Ca_cmca_1_5_boa__-2.0_4 \<br> Ca_cmca_1_5_boa___0.0_4 \<br>
Ca_cmca_1_5_boa___2.0_4 \<br> Ca_cmca_1_5_boa___4.0_4 \<br> )<br> rm Ca_cmca_1_5.struct # NFS-bug<br> cp $i.struct Ca_cmca_1_5.struct<br>
<br> # Please uncomment and adapt any of the lines below according to your needs<br> # cp $i.clmsum Ca_cmca_1_5.clmsum<br> x dstart<br> # x dstart -c<br> # run_lapw -ec 0.0001 -in1new 3 -in1orig -renorm<br> # runsp_lapw -ec 0.0001<br>
min -I -j "run_lapw -p -fc 0.1 -i 200 -NI "<br> # run_lapw -ec 0.0001<br><br> set stat = $status<br> if ($stat) then<br> echo "ERROR status in" $i<br> exit 1<br> endif<br> # save_lapw $i<br>
save_lapw -f -d /home/victor/wien2k_07/Ca_cmca_1_5/final $i<br> end<br>**********************************************************<br><br>-- I also changed *.inM file, changed the force tolerance form 2 to 0.1<br>mRy/a.u., I found the default value is<br>
too high.<br><br>-- finally I run the script "optimize.job"<br><br>After the calculations, I got the results as I stated before.<br><br> Thank you very much!<br><br>Yours<br><br>Victor<br>_______________________________________________<br>
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</blockquote></div><br><br clear="all"><br>-- <br>SUSANTA K MOHANTA<br>RESEARCH SCHOLAR<br>DEPT.OF PHYSICS<br>IIT KHARAGPUR<br>*****************************