[Wien] Space group P4(2)/nmc (137)

Peter Blaha pblaha at theochem.tuwien.ac.at
Thu Mar 26 15:29:07 CET 2015


Yes, this space group has   2 different "settings".

Wien2k needs the one with inversion symmetry (it has a (-x,-y,-z) 
operation (in the general 16h position), while the "wrong" setting has a 
(1/2-x,1/2-y,1/2-z) instead.

when you compare the positions, you also see what you have to change:


2a: 0,0,0 --> 1/4,3/4,1/4   (and you should specify only one Zr)
4d: 0,.5,.185 --> 1/4,1/4,1/4+.185



On 03/26/2015 02:51 PM, Ary Ferreira wrote:
> Please,
>
> I'm trying to use the makestruct script to build the structure of
> tetragonal zirconia. According to [Acta Cryst. (1962). 15, 1187], the
> space group is P4(2)/nmc (137), the parameters are a = 3.64 Ang., c
> =5.27 Ang., and there are 6 atomic positions in the full cell:
>
> [symbol] [id] [WP] [x] [y] [z]
> Zr 1 2a 0.0000 0.0000 0.0000
> Zr 2 2a 0.5000 0.5000 0.5000
> O 1 4d 0.0000 0.5000 0.1850
> O 2 4d 0.5000 0.0000 -0.1850
> O 3 4d 0.0000 0.5000 0.6850
> O 4 4d 0.5000 0.0000 0.3150
>
> I could build these coordinates taking the Zr(1) and the O(1) and the
> symmetry operations of the space group. The structure and atomic
> distances are the same of the reported crystallographic data. However,
> when I try to use the makestruct script entering with the space group
> and these two coordinates, the structure created have a huge number of
> atoms. Is this space group another case for which it is necessary to
> transform to another one using
> SETSTRU(http://www.cryst.ehu.es/cryst/setstru.html
> <http://www.cryst.ehu.es/cryst/setstru.html>)? Below is how I' using the
> script:
>
> ************************************************
> *                                              *
> **********   Terminal struct maker    **********
> ********** (C) 2012 by Morteza Jamal  **********
> *                                              *
> ************************************************
> TITLE :TZIRCONIA
>
>   This Program accepts a SPACE GROUP  (symbol or number)   or a
>                          LATTICE TYPE (P, F, B, H, R, CXY, CXZ, CYZ ).
>   But, with LATTICE TYPE YOU HAVE TO put in all the atomic positions by
> hand.
>
> Would you like to enter  Spacegroup or Lattice (S/L)(def=S)?
> SPACE GROUP: (type ENTER or give first LETTER for a list)
> give SPACE GROUP as SYMBOL or NUMBER: 137
>   Info:  space group is : 137 P P42/nmc -P4ac;-2a
>
> Units of lattice parameters (Bohr/Angstrom) (b/A) (def=ANG):
> Lattice PARAMETERS as a b c (3 numbers):3.64000 3.64000 5.27000
> ANGLES BETWEEN lattice vectors, as alpha beta gamma (def=90.0 90.0 90.0):
> NUMBER INEQUEVALENT ATOMS :2
> ATOM  1 (ELEMENT): Zr
> POSITION OF ATOM Zr as X,Y,Z (def=0 0 0) :0.0000 0.0000 0.0000
> ATOM  2 (ELEMENT): O
> POSITION OF ATOM O as X,Y,Z (def=0 0 0) :0.0000 0.5000 0.1850
>
>   Now, 'datastruct' file is ready.
> We Run 'Tmaker' for making WIEN2k struct file.
>
>   P42/nmc
>     6.87860583509865        6.87860583509865        9.95886064587085
>     90.0000000000000        90.0000000000000        90.0000000000000
>   ATOM NAME:Zr
>   Zr/1        0.00000000  0.00000000  0.00000000
>   Zr/2        0.50000000  0.00000000  0.50000000
>   Zr/3        0.50000000  0.00000000  0.00000000
>   Zr/4        0.50000000  0.50000000  0.00000000
>   Zr/5        0.50000000  0.50000000  0.50000000
>   Zr/6        0.00000000  0.50000000  0.50000000
>   Zr/7        0.00000000  0.50000000  0.00000000
>   Zr/8        0.00000000  0.00000000  0.50000000
>   ATOM NAME:O
>   O/1         0.00000000  0.50000000  0.18500000
>   O/2         0.00000000  0.50000000  0.81500000
>   O/3         0.00000000  0.00000000  0.68500000
>   O/4         0.00000000  0.00000000  0.31500000
>   O/5         0.50000000  0.50000000  0.18500000
>   O/6         0.50000000  0.50000000  0.81500000
>   O/7         0.50000000  0.00000000  0.18500000
>   O/8         0.50000000  0.00000000  0.81500000
>   O/9         0.00000000  0.50000000  0.68500000
>   O/10        0.00000000  0.50000000  0.31500000
>   O/11        0.50000000  0.50000000  0.68500000
>   O/12        0.50000000  0.50000000  0.31500000
>   O/13        0.00000000  0.00000000  0.18500000
>   O/14        0.00000000  0.00000000  0.81500000
>   O/15        0.50000000  0.00000000  0.68500000
>   O/16        0.50000000  0.00000000  0.31500000
>
>   'init.struct' file is ready
>
> SETTING UP SPHERE RadII:
> SPECIFY possible REDUCTION of SPHERE RADII in % (def=0)
> 0.1
>   specify nn-bondlength factor: (usually=2) [and optionally dlimit,
> dstmax (about
>    1.d-5, 20)]
>   DSTMAX:   20.0000000000000
>   iix,iiy,iiz           4           4           3   27.5144240000000
>     27.5144240000000        29.8765830000000
>
>     ERROR !!!!!!!!!!!!!!!
>   RMT(  1)=2.00000 AND RMT(  2)=2.00000
>   SUMS TO 4.00000 GT NNN-DIST= 1.84239
>
>     ERROR !!!!!!!!!!!!!!!
>   RMT(  1)=2.00000 AND RMT(  1)=2.00000
>   SUMS TO 4.00000 GT NNN-DIST= 3.43930
>
>     ERROR !!!!!!!!!!!!!!!
>   RMT(  2)=2.00000 AND RMT(  2)=2.00000
>   SUMS TO 4.00000 GT NNN-DIST= 1.29465
>
>     ERROR !!!!!!!!!!!!!!!
>   RMT(  2)=2.00000 AND RMT(  1)=2.00000
>   SUMS TO 4.00000 GT NNN-DIST= 1.84239
> NN ENDS
> 0.124u 0.004s 0:00.13 92.3%    0+0k 0+376io 0pf+0w
> atom  Z   RMT-max   RMT
>   1  40.0  0.96   0.96
>   2   8.0  0.64   0.64
> file    init.struct_setrmt   generated
> rerun setrmt ?(y,N) (def=N):
>
> The file   init.struct   has been created
>
>    for modifications of your input you can also edit file datastruct and run
>    Tmaker / setrmt init -r X    individually
>
> Thank you very much,
>
> Ary Ferreira
>
> --
> http://lattes.cnpq.br/8221674673413336
>
>
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-- 

                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-165300             FAX: +43-1-58801-165982
Email: blaha at theochem.tuwien.ac.at    WIEN2k: http://www.wien2k.at
WWW:   http://www.imc.tuwien.ac.at/staff/tc_group_e.php
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