Thank you Gavin Abo,
I got your point. As I understood from this forum discussions, for
Rhombohedral lattice one should always use primitive basis coordinate of
high symmetry point for generating case.klist_band using xcrysden. In my
case compound have space group R-3c (167) and lattice parameter sqrt(3a) <
(sqrt2c). So I generated the case.klist_band by manual labeling the high
symmetry point in xcrysden, I have taken the high symmetric point
coordinate in primitive basis from the bilbao server
http://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-kv-list. The band
structure calculation have done along Gama-T-L-FB-Gama-T-L directions. The
primitive basis coordinate used as Gama(0 0 0), T (1/2 1/2 1/2), L (0 1/2
0), FB (0 1/2, 1/2). I dont know what one can take the value of u (it
should be less than or = 1 in primitive basis coordinate),If I know u
value, I could have included one more symmetry point LD(u u u). Can you
suggest the proper value of u.  I hope that I have generated
case.klist_band properly and calculated band structure correctly.
Please give your comment on the way i did the band structure calculation,
if you feel that there is any correction require then give your suggestion
to do the correct band structure calculation
<http://www.mail-archive.com/search?l=wien@zeus.theochem.tuwien.ac.at&q=from:%22Gavin+Abo%22>

On Mon, May 16, 2016 at 12:20 PM, saurabh singh <saurabhiitma...@gmail.com>
wrote:

> Thank you so much Peter BLAHA Sir for your valuable suggestion .
> I have another query, In the Bilbao crystallographic server the k-vector
> description is given in the two basis i.e. *Primitive basis and  
> **Conventional
> basis *. In the user manual of Wien2k section 7.5.3 page 120, ix,iy,iz,
> defines the k-vector, where x= ix/idv etc. We use cartesian coordinates in
> units of 2π/a, 2π/b, 2π/c for P,C,F and B cubic, tetragonalnand
> orthorhombic lattices, but internal coordinates for H and
> monoclinic/triclinic lattices.
> For rhombohedral there is no suggestion given.
> Since we need to select the k-point manually in the xcrysden for high
> symmetric k-point, therefore it is very important to choose the correct
> basis coordinate. therefore I would like to know that in general for
> Rhombohedral space group, which basis coordinate (Primitive or
> Conventional) given in the Bilbao server should be used for making the
> case.klist_band.
>  I have two choice in xcrysden:
> 1. Primitive Brillouin zone: if I choose this option in xcrysden to select
> the k-point coordinate then should i use the primitive basis coordinate of
> high k-point from the Bilbao server.
> 2. Conventional Brillouin zone: for this should i use the conventional
> basis coordinate from the Bilbao server.
>
> Please give your suggestion for choosing the proper basis coordinate of
> k-point for rhmbohedral lattice from Bilbao server.
>
> On Sun, May 15, 2016 at 10:48 PM, saurabh singh <saurabhiitma...@gmail.com
> > wrote:
>
>> Dear All Wien2k users,
>>
>> We want to calculate the band structure of LaCoO3 compound. The space
>> group of this compound is R-3c (No. 167). In the Wien2k user manual, it is
>> suggested for R lattice to use rhombohedral coordinates. Therefore we made
>> the case.structure file using lattice parameters a=b= 10.2541 Bohr, c=
>> 24.5494, alpha=beta=90 degree, gamma = 120 degree, and converted
>> rhombohedral coordinates for each atom. When we try to make case.klist_band
>> file by selecting the case.structure folder path in xcrysden, it says " the
>> guessed bravais lattice type: not supported (the XSF's group number is 7).
>> We tried the two different way to get the case.klist_band as follows:
>>
>> 1) Firstly, we have changed the lattice parameters in case.structure file
>> in accordance to rhombohedral structure. We thought if the lattice
>> parameters and atomic coordinate both will be accordance to rhombohedral
>> then xcrysden can recognize the case.struct file. But again case.struct
>> file does not recognized by xcrysden.
>>
>> 2) Secondly, we took the hcp.klist file given in wien2k SRC folder, which
>> is as follows:
>> GAMMA  0    0    0   40  2.0-0.5 1.5       Template for hcp structure
>>               1    0    0   40  2.0
>>               2    0    0   40  2.0
>>               3    0    0   40  2.0
>>               4    0    0   40  2.0
>>               5    0    0   40  2.0
>>               6    0    0   40  2.0
>>               7    0    0   40  2.0
>>               8    0    0   40  2.0
>>               9    0    0   40  2.0
>> SIGMA  10    0    0   40  2.0
>>              11    0    0   40  2.0
>>              12    0    0   40  2.0
>>              13    0    0   40  2.0
>>              14    0    0   40  2.0
>>              15    0    0   40  2.0
>>              16    0    0   40  2.0
>>              17    0    0   40  2.0
>>              18    0    0   40  2.0
>>              19    0    0   40  2.0
>> M            20    0    0   40  2.0
>>              29    2    0   60  2.0
>>              28    4    0   60  2.0
>>              27    6    0   60  2.0
>>              26    8    0   60  2.0
>>              25   10    0   60  2.0
>>              24   12    0   60  2.0
>>              23   14    0   60  2.0
>>              22   16    0   60  2.0
>>              21   18    0   60  2.0
>> K           20   20    0   60  2.0
>>              19   19    0   60  2.0
>>              18   18    0   60  2.0
>>              17   17    0   60  2.0
>>              16   16    0   60  2.0
>>              15   15    0   60  2.0
>>              14   14    0   60  2.0
>>              13   13    0   60  2.0
>>              12   12    0   60  2.0
>>              11   11    0   60  2.0
>> LAMBDA10   10    0   60  2.0
>>               9    9    0   60  2.0
>>               8    8    0   60  2.0
>>               7    7    0   60  2.0
>>               6    6    0   60  2.0
>>               5    5    0   60  2.0
>>               4    4    0   60  2.0
>>               3    3    0   60  2.0
>>               2    2    0   60  2.0
>>               1    1    0   60  2.0
>> GAMMA  0    0    0   60  2.0
>>               0    0    1   20  2.0
>>               0    0    2   20  2.0
>>               0    0    3   20  2.0
>>               0    0    4   20  2.0
>> DELTA    0    0    5   20  2.0
>>               0    0    6   20  2.0
>>               0    0    7   20  2.0
>>               0    0    8   20  2.0
>>               0    0    9   20  2.0
>> A            0    0   10   20  2.0
>> END
>>
>> We renamed this hcp.klist file as case.klist_band and used it for band
>> structure calculation. The calculated band structure gives the indirect
>> band gap which is almost equal to the band gap obtained from SCF
>> calculation.
>>
>> My question is, whether we can use the hcp.klist (given in Wien2k SRC
>> folder) as case.klist_band for band structure calculation if the compound
>> have R-3c space group and having the hexagonal lattice parameter and
>> rhombohedral atomic coordinate in the case.struct file. Please let me know
>> I am doing right or there is some different way to do it.
>>
>
>
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