Checkout the pictures of the space group in the 2 settings. It should be pretty clear.

Am 16.05.2016 um 08:50 schrieb saurabh singh:
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 <mailto: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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