[Wien] a question about geometry optimization on Ca_cmca

[susanta mohanta]

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..

On Wed, Jul 9, 2008 at 6:25 PM, zhs064 <zhs064 at mail.usask.ca> wrote:

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



-- 
SUSANTA K MOHANTA
RESEARCH SCHOLAR
DEPT.OF PHYSICS
IIT KHARAGPUR
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