[Wien] a question about geometry optimization on Ca_cmca

zhs064 zhs064 at mail.usask.ca
Thu Jul 10 17:36:11 CEST 2008


Dear Peter & Susanta,

         Thank you very much for your replies.

>Have you checked if :LAT  is modified the way you want it in the newly
>regenerated struct files ?

Yes, I checked, the lattice constants (:LAT) are just what I wanted.

   

>Are you just saying, that E-tot has a minimum very close to the original minimun ?
>That would just mean that the previous optimization was ok.
>Or are you saying that a,b,c don't change in the generated struct files ???

I mean the a, b, c don't change in the generated structure files.

>PS: Please remember,   x optimize uses by default a file case_initial.struct (if present).
>You need to select manually the proper struct file or copy it to this file

Yes, I noticed this problem, whenever I wanna generate structure files, I always copy the object structure
file to case.struct and case_initial.struct.

 
Thank you very much!

Yours

Victor

       

Peter Blaha wrote:
> In principle the procedure you describe looks ok.
>
> Have you checked if :LAT  is modified the way you want it in the newly
> renerated struct files ?
>
>  > volumes. The question is I found the optimized cell constants don't
>  > change and the atomic positions changed
>
> Are you just saying, that E-tot has a minimum very close to the original minimun ?
> That would just mean that the previous optimization was ok.
>
> Or are you saying that a,b,c don't change in the generated struct files ???
>
> PS: Please remember,   x optimize uses by default a file case_initial.struct (if present).
> You need to select manually the proper struct file or copy it to this file
>
> zhs064 schrieb:
>   
>> 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
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>     
>
>   



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