[Wien] a question about geometry optimization on Ca_cmca

[Peter Blaha]

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

-- 

                                       P.Blaha
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
--------------------------------------------------------------------------