[Pw_forum] ibrav7 doesn't show the structure of BaNi2As2 correctly

[David Foster]

Dear users

The atomic positions for BaNi2As2 crystal with space group of I4/mmm (139) are:

Ba (2a): 0, 0,   0 
As (4e): 0, 0,   0.3471 
Ni(4d):   0, 0.5, 0.25

I used MS Visualizer to build the conventional tetragonal cell (a = b = 4.1474  c = 11.619).

After seeing the structure with MS, I convert it to primitive and finding all atoms positions. Only 5 atoms there are in primitive (If I am right):

Ba 0.000000 0.000000  0.000000
As 0.347100 0.347100  0.000000
As 0.652900 0.652900  0.000000
Ni 0.750000 0.250000  0.500000
Ni 0.250000 0.750000  0.500000

I prepared two input file for QE5.0.3, one with ibrav=7 and 5 atoms, and the other with ibrav=14 and all atoms in conventional cell instead of its primitive:
with P1 symmetry, the cell has 10 atoms:
Ba 0.0000 0.0000  0.0000
Ba 0.5000 0.5000  0.5000
As 0.000 0.000  0.3471
As 0.5000 0.5000  0.8471
As 0.000 0.000  0.6529
As 0.5000 0.5000  0.1529
Ni 0.000 0.5000  0.25000
Ni 0.500 0.0000  0.250000
Ni 0.000 0.5000  0.75000
Ni 0.500 0.0000  0.750000

I have attached two inputs and two pictures that xcrysden shows. While ibrav=14 shows the crystal correctly, ibrav=7 has a problem and doesn't show the crystal properly. I am confused!!
Any help will be appreciated.



Then, I 
 
Regards

David Foster

Ph.D. Student of Chemistry
-------------- next part --------------
A non-text attachment was scrubbed...
Name: banias_ibrav7.in
Type: application/octet-stream
Size: 843 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20140527/92d76551/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: banias_ibrav14.in
Type: application/octet-stream
Size: 1027 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20140527/92d76551/attachment-0001.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pwi2xsf_ibrav7.png
Type: image/png
Size: 36616 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20140527/92d76551/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pwi2xsf_ibrav14.png
Type: image/png
Size: 93945 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20140527/92d76551/attachment-0001.png>