[Wien] The symmetry is not recognized by Wien
Peter Blaha
pblaha at theochem.tuwien.ac.at
Thu Oct 20 15:35:35 CEST 2011
As I said, before, I'm answering ONLY over the mailing list. I cannot teach crystallography
to all 2000 users individually.
Looking at your first struct file, I can assume that you used properly the hexagonal
lattice parameters a and c .
So here is nothing to change.
The position of the first atom you specified with a 18-fold multiplicity and this
tells me immediately that you entered the hexagonal coordinates. Apparently VASP
made the calculations in a 3 times larger unit cell than necessary.
Have a look at the International Tables of Cryst, eg. at the Bilbao server
(link from w2web). For SG 148 there are 2 settings listed, a hexagonal and a
rhombohedral one. The rhombohedral one has max mulltiplicity of 6 (6f site),
the hexagonal one has 18f.
As I mentioned before: You must enter the rhombohedral ones, thus execute
hex2rhomb and enter the position of the first atom. It will convert:
input hex
0.34298000 0.20230000 0.41446000
out put rho
0.27378000 0.75744000 0.21216000
These latter 3 values you should put into w2web/structgen for the first site.
There is NO NEED to convert any of the other 17 equivalent positions, this
will be generated automatically by WIEN2k.
If not yet clear, a second example: Your 3rd atom is located at position 3b
input hex
0.00000000 0.00000000 0.50000000
out put rho
0.50000000 0.50000000 0.50000000
which corresponds to the rhombohedral position 1b, which is according to
the Bilbao server at (0.5,0.5,0.5) and this is what hex2rhomb gave.
Just enter (.5,.5,.5) for the 3rd atom.
Basically the input in w2web/structgen is as simple as:
SG 148 (R-3)
10.426753 10.426753 25.380912 90.000000 90.000000 120.000000
O 0.27378000 0.75744000 0.21216000
Sr 0.25003000 0.25003000 0.25003000
Ru 0.5 0.5 0.5
Cr 0 0 0
The rest will be done automatically and should produce 6,2,1,1 fold multiplicities.
--
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/
--------------------------------------------------------------------------
Sir,
Sorry to bother you in your private mail. I list my question titled "The symmetry is not recognized by Wien" in mailing list earlier today. However, I still have something to
consult.
My structure uploaded to Wien is as follows:
____________________________________________________________
blebleble
H LATTICE,NONEQUIV.ATOMS 4 148 R-3
MODE OF CALC=RELA unit=bohr
10.426753 10.426753 25.380912 90.000000 90.000000120.000000
ATOM -1: X=0.34298000 Y=0.20230000 Z=0.41446000
MULT=18 ISPLIT=15
-1: X=0.79770000 Y=0.14068000 Z=0.41446000
-1: X=0.85932000 Y=0.65702000 Z=0.41446000
-1: X=0.65702000 Y=0.79770000 Z=0.58554000
-1: X=0.20230000 Y=0.85932000 Z=0.58554000
-1: X=0.14068000 Y=0.34298000 Z=0.58554000
-1: X=0.00964667 Y=0.53563333 Z=0.74779333
-1: X=0.46436667 Y=0.47401333 Z=0.74779333
-1: X=0.52598667 Y=0.99035333 Z=0.74779333
-1: X=0.32368667 Y=0.13103333 Z=0.91887333
-1: X=0.86896667 Y=0.19265333 Z=0.91887333
-1: X=0.80734667 Y=0.67631333 Z=0.91887333
-1: X=0.67631333 Y=0.86896667 Z=0.08112667
-1: X=0.13103333 Y=0.80734667 Z=0.08112667
-1: X=0.19265333 Y=0.32368667 Z=0.08112667
-1: X=0.99035333 Y=0.46436667 Z=0.25220667
-1: X=0.53563333 Y=0.52598667 Z=0.25220667
-1: X=0.47401333 Y=0.00964667 Z=0.25220667
O NPT= 781 R0=.000100000 RMT= 2.00000 Z: 8.00000
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
0.0000000 1.0000000 0.0000000
0.0000000 0.0000000 1.0000000
ATOM -2: X=0.00000000 Y=0.00000000 Z=0.25003000
MULT= 6 ISPLIT=15
-2: X=0.00000000 Y=0.00000000 Z=0.74997000
-2: X=0.66666667 Y=0.33333333 Z=0.58336333
-2: X=0.66666667 Y=0.33333333 Z=0.08330333
-2: X=0.33333333 Y=0.66666667 Z=0.91669667
-2: X=0.33333333 Y=0.66666667 Z=0.41663667
Sr NPT= 781 R0=.000010000 RMT= 2.00000 Z: 38.00000
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
0.0000000 1.0000000 0.0000000
0.0000000 0.0000000 1.0000000
ATOM -3: X=0.00000000 Y=0.00000000 Z=0.50000000
MULT= 3 ISPLIT=15
-3: X=0.66666667 Y=0.33333333 Z=0.83333333
-3: X=0.33333333 Y=0.66666667 Z=0.16666667
Ru NPT= 781 R0=.000010000 RMT= 2.00000 Z: 44.00000
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
0.0000000 1.0000000 0.0000000
0.0000000 0.0000000 1.0000000
ATOM -4: X=0.00000000 Y=0.00000000 Z=0.00000000
MULT= 3 ISPLIT=15
-4: X=0.66666667 Y=0.33333333 Z=0.33333333
-4: X=0.33333333 Y=0.66666667 Z=0.66666667
Cr NPT= 781 R0=.000050000 RMT= 2.00000 Z: 24.00000
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
_______________________________________________________________________
After setting RMT and “save file and clean up” the .structure file is:
_______________________________________________________________________
Sr2CrRuO6
R LATTICE,NONEQUIV.ATOMS: 4148_R-3
MODE OF CALC=RELA unit=bohr
10.426753 10.426753 25.380912 90.000000 90.000000120.000000
ATOM -1: X=0.34297999 Y=0.20230000 Z=0.41446000
MULT= 6 ISPLIT= 8
ATOM -1:X= 0.65702001 Y=0.79770000 Z=0.58554000
ATOM -1:X= 0.20230000 Y=0.41446000 Z=0.34297999
ATOM -1:X= 0.79770000 Y=0.58554000 Z=0.65702001
ATOM -1:X= 0.41446000 Y=0.34297999 Z=0.20230000
ATOM -1:X= 0.58554000 Y=0.65702001 Z=0.79770000
O NPT= 781 R0=0.00010000 RMT= 0.9500 Z: 8.0
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
0.0000000 1.0000000 0.0000000
0.0000000 0.0000000 1.0000000
ATOM -2: X=0.99999998 Y=0.00000000 Z=0.25003000
MULT= 6 ISPLIT= 8
ATOM -2:X= 0.00000002 Y=0.00000000 Z=0.74997000
ATOM -2:X= 0.00000000 Y=0.25003000 Z=0.99999998
ATOM -2:X= 0.00000000 Y=0.74997000 Z=0.00000002
ATOM -2:X= 0.25003000 Y=0.99999998 Z=0.00000000
ATOM -2:X= 0.74997000 Y=0.00000002 Z=0.00000000
Sr NPT= 781 R0=0.00001000 RMT= 1.1900 Z: 38.0
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
0.0000000 1.0000000 0.0000000
0.0000000 0.0000000 1.0000000
ATOM -3: X=0.00000001 Y=0.00000000 Z=0.50000000
MULT= 3 ISPLIT= 8
ATOM -3:X= 0.00000000 Y=0.50000000 Z=0.00000001
ATOM -3:X= 0.50000000 Y=0.00000001 Z=0.00000000
Ru NPT= 781 R0=0.00001000 RMT= 1.3400 Z: 44.0
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
0.0000000 1.0000000 0.0000000
0.0000000 0.0000000 1.0000000
ATOM -4: X=0.00000000 Y=0.00000000 Z=0.00000000
MULT= 1 ISPLIT= 8
Cr NPT= 781 R0=0.00005000 RMT= 1.3400 Z: 24.0
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
______________________________________________________________________
I doubt the saved structure file has already used the rhombohedral coordinates. doesn’t it?
I also tried to use “hex2rhomb” program. It is required for “hx, hy, hz”, so I entered the lattice parameters. The structure file did not change.
So where is matter?
Wang J
wangjingjing at ciac.jl.cn
2011-10-20
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