[Wien] Si under strain

Muhammad Sajjad sajjadpu at gmail.com
Thu Sep 10 15:33:07 CEST 2015


Actually I downloaded structure from COD base. So you are write its space
group is fd3m and structure is Title

F   LATTICE,NONEQUIV.ATOMS:  1 227_Fd-3m
MODE OF CALC=RELA unit=ang
 10.263031 10.263031 10.263031 90.000000 90.000000 90.000000
ATOM  -1: X=0.00000000 Y=0.00000000 Z=0.00000000
          MULT= 4          ISPLIT= 8
ATOM  -1:X= 0.00000000 Y=0.25000000 Z=0.25000000
ATOM  -1:X= 0.25000000 Y=0.25000000 Z=0.00000000
ATOM  -1:X= 0.25000000 Y=0.00000000 Z=0.25000000
Si         NPT=  781  R0=0.00010000 RMT=    1.8000   Z: 14.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                     0.0000000 1.0000000 0.0000000
                     0.0000000 0.0000000 1.0000000
   0      NUMBER OF SYMMETRY OPERATIONS .

But strain application ((a =5.49 , b= 5.43 , c = 5.38)) does not allow
fd-3m, definitely symmetry changed. If is make it primitive, it will be ok
or not?

On Thu, Sep 10, 2015 at 4:24 PM, Fecher, Gerhard <fecher at uni-mainz.de>
wrote:

> Then
> https://www.webelements.com/silicon/crystal_structure.html
> is wrong !
>
> Before you start calculations you should know the crystal structure very
> well and you should know about symmetry and space groups.
>
> Ciao
> Gerhard
>
> DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
> "I think the problem, to be quite honest with you,
> is that you have never actually known what the question is."
>
> ====================================
> Dr. Gerhard H. Fecher
> Institut of Inorganic and Analytical Chemistry
> Johannes Gutenberg - University
> 55099 Mainz
> and
> Max Planck Institute for Chemical Physics of Solids
> 01187 Dresden
> ________________________________________
> Von: wien-bounces at zeus.theochem.tuwien.ac.at [
> wien-bounces at zeus.theochem.tuwien.ac.at] im Auftrag von Muhammad Sajjad [
> sajjadpu at gmail.com]
> Gesendet: Donnerstag, 10. September 2015 14:51
> An: A Mailing list for WIEN2k users
> Betreff: Re: [Wien] Si under strain
>
> It is 216_F-43m
>
> On Thu, Sep 10, 2015 at 1:51 PM, Muhammad Sajjad <sajjadpu at gmail.com
> <mailto:sajjadpu at gmail.com>> wrote:
> Here is the structure file script.
>
>
> Title
> F   LATTICE,NONEQUIV.ATOMS:  2 216_F-43m
> MODE OF CALC=RELA unit=ang
>  10.263031 10.263031 10.263031 90.000000 90.000000 90.000000
> ATOM   1: X=0.00000000 Y=0.00000000 Z=0.00000000
>           MULT= 1          ISPLIT= 2
> Si         NPT=  781  R0=0.00010000 RMT= 2.21        Z: 14.0
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
> ATOM   2: X=0.25000000 Y=0.25000000 Z=0.25000000
>           MULT= 1          ISPLIT= 2
> Si         NPT=  781  R0=0.00010000 RMT= 2.21        Z: 14.0
> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>                      0.0000000 1.0000000 0.0000000
>                      0.0000000 0.0000000 1.0000000
>   24      NUMBER OF SYMMETRY OPERATIONS
>  1 0 0 0.00000000
>  0-1 0 0.00000000
>  0 0-1 0.00000000
>        1
>  1 0 0 0.00000000
>  0 0-1 0.00000000
>  0-1 0 0.00000000
>        2
>  0 1 0 0.00000000
> -1 0 0 0.00000000
>  0 0-1 0.00000000
>        3
>  0 0 1 0.00000000
> -1 0 0 0.00000000
>  0-1 0 0.00000000
>        4
>  0 1 0 0.00000000
>  0 0-1 0.00000000
> -1 0 0 0.00000000
>        5
>  0 0 1 0.00000000
>  0-1 0 0.00000000
> -1 0 0 0.00000000
>        6
>  0-1 0 0.00000000
>  1 0 0 0.00000000
>  0 0-1 0.00000000
>        7
>  0 0-1 0.00000000
>  1 0 0 0.00000000
>  0-1 0 0.00000000
>        8
> -1 0 0 0.00000000
>  0 1 0 0.00000000
>  0 0-1 0.00000000
>        9
> -1 0 0 0.00000000
>  0 0 1 0.00000000
>  0-1 0 0.00000000
>       10
>  0-1 0 0.00000000
>  0 0-1 0.00000000
>  1 0 0 0.00000000
>       11
>  0 0-1 0.00000000
>  0-1 0 0.00000000
>  1 0 0 0.00000000
>       12
>  0 0 1 0.00000000
>  0 1 0 0.00000000
>  1 0 0 0.00000000
>       13
>  0 1 0 0.00000000
>  0 0 1 0.00000000
>  1 0 0 0.00000000
>       14
> -1 0 0 0.00000000
>  0 0-1 0.00000000
>  0 1 0 0.00000000
>       15
> -1 0 0 0.00000000
>  0-1 0 0.00000000
>  0 0 1 0.00000000
>       16
>  0 0 1 0.00000000
>  1 0 0 0.00000000
>  0 1 0 0.00000000
>       17
>  0 1 0 0.00000000
>  1 0 0 0.00000000
>  0 0 1 0.00000000
>       18
>  0 0-1 0.00000000
>  0 1 0 0.00000000
> -1 0 0 0.00000000
>       19
>  0-1 0 0.00000000
>  0 0 1 0.00000000
> -1 0 0 0.00000000
>       20
>  0 0-1 0.00000000
> -1 0 0 0.00000000
>  0 1 0 0.00000000
>       21
>  0-1 0 0.00000000
> -1 0 0 0.00000000
>  0 0 1 0.00000000
>       22
>  1 0 0 0.00000000
>  0 0 1 0.00000000
>  0 1 0 0.00000000
>       23
>  1 0 0 0.00000000
>  0 1 0 0.00000000
>  0 0 1 0.00000000
>       24
>
>
> On Wed, Sep 9, 2015 at 10:52 PM, Gavin Abo <gsabo at crimson.ua.edu<mailto:
> gsabo at crimson.ua.edu>> wrote:
> Did you send the wrong scfmbj.struct?  At least for me, "x nn" of WIEN2k
> 14.2 gives WARNINGS that the struct file is not okay.
>
> username at computername:~/wiendata/scfmbj$ ls
> scfmbj.struct
> username at computername:~/wiendata/scfmbj$ x nn
>  specify nn-bondlength factor: (usually=2) [and optionally dlimit, dstmax
> (about
>   1.d-5, 20)]
> 2
>  DSTMAX:   20.0000000000000
>  iix,iiy,iiz           4           4           5   41.0521240000000
>    41.0521240000000        51.3151550000000
>
>     ATOM  1  Si         ATOM  2  Si
>  RMT(  1)=2.21000 AND RMT(  2)=2.21000
>  SUMS TO 4.42000  LT.  NN-DIST= 4.44402
>
>     ATOM  2  Si         ATOM  1  Si
>  RMT(  2)=2.21000 AND RMT(  1)=2.21000
>  SUMS TO 4.42000  LT.  NN-DIST= 4.44402
>  WARNING: Mult not equal. PLEASE CHECK outputnn-file
>  WARNING: Mult not equal. PLEASE CHECK outputnn-file
>  WARNING: ityp not equal. PLEASE CHECK outputnn-file
>
>   NN created a new scfmbj.struct_nn file
> NN created a new CASE.STRUCT_NN FILE
> 0.0u 0.0s 0:01.35 0.0% 0+0k 0+32io 0pf+0w
>
>
> On 9/9/2015 8:48 AM, Muhammad Sajjad wrote:
> Dear user
> I computed Si BS for the structure (scfmbj.struct) attached herewith. When
> I apply strain (a+a*0.01, b, c-c*0.01) then symmetry changes (space group
> 1_P1). WIth this group calculations does not run every times QTLB error
> appears and I have done my best to apply each solution for it.
> Secondly I got structure from wien2k examples. That works fine but when
> strain is applied then it behaves as a metal. Though this work has been
> done many times but I can not find my solution. I found VASP study but not
> wien2k study.
> In VASP POSCAR is
> cubic diamond
>    5.50000000000000
>      0.0000000000000000    0.4969432792132343    0.4969432792132343
>      0.4969432792132343    0.0000000000000000    0.4969432792132343
>      0.4969432792132343    0.4969432792132343    0.0000000000000000
>    Si
>      2
> Direct
>   0.8750000000000000  0.8750000000000000  0.8750000000000000
>   0.1250000000000000  0.1250000000000000  0.1250000000000000
>
> I changed this POSCAR to cif and used for wien2k (structure is attached
> TEST.struct) , then BS is correct, but after application of strain (1%)
> again it becomes metal.
> I do not know how to apply strain in POSCAR.
> Could you please guide me?
>
> Kind Regards
> Muhammad Sajjad
> Post Doctoral Fellow
> KAUST, KSA.
>
> _______________________________________________
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>
>
>
>
> --
> Kind Regards
> Muhammad Sajjad
> Post Doctoral Fellow
> KAUST, KSA.
>
>
>
> --
> Kind Regards
> Muhammad Sajjad
> Post Doctoral Fellow
> KAUST, KSA.
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:
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>



-- 
Kind Regards
Muhammad Sajjad
Post Doctoral Fellow
KAUST, KSA.
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