[Wien] Parity of bands of non-symmorphic space group

M. Arshad Farhan arshadfarhan at gmail.com
Wed Jun 29 06:24:24 CEST 2016


Dear Wien2k developers/users,
hi,
i'm trying to calculate the parity of bands at different K-points (with
inclusion of SOC)

I used the script "$irrep -so" but it seems that space group of my system
is non-symmorphic.
also the k-point i'm interested in lies on the edge of 1st BZ

the output is as following:

"
knum =  1    kname=          1
k = 0.500000 0.500000 0.000000
       The point group is D4h
       16 symmetry operations in 10 classes
       Table 40   on page  50 in Koster  et al [7]
       Table 33.4 on page 258 in Altmann et al [8]
                   E   2C4    C2   2C2`  2C2"    I  2IC4   IC2  2IC2` 2IC2"
       G1+   A1g   1     1     1     1     1     1     1     1     1     1
       G2+   A2g   1     1     1    -1    -1     1     1     1    -1    -1
       G3+   B1g   1    -1     1     1    -1     1    -1     1     1    -1
       G4+   B2g   1    -1     1    -1     1     1    -1     1    -1     1
       G5+   Eg    2     0    -2     0     0     2     0    -2     0     0
       G1-   A1u   1     1     1     1     1    -1    -1    -1    -1    -1
       G2-   A2u   1     1     1    -1    -1    -1    -1    -1     1     1
       G3-   B1u   1    -1     1     1    -1    -1     1    -1    -1     1
       G4-   B2u   1    -1     1    -1     1    -1     1    -1     1    -1
       G5-   Eu    2     0    -2     0     0    -2     0     2     0     0
       --------------------------------------------------------------------
       G6+   E1/2g 2     /2    0     0     0     2     /2    0     0     0
       G7+   E3/2g 2    -/2    0     0     0     2    -/2    0     0     0
       G6-   E1/2u 2     /2    0     0     0    -2    -/2    0     0     0
       G7-   E3/2u 2    -/2    0     0     0    -2     /2    0     0     0

       labeling of IRs can change due to choice of
       symmetry axes: G3 <-> G4

       Non-symmorphic crystal and k-point at the BZ surface:
       IR of the space group for this k-point cannot simple
       be expressed as IR of the corresponding point group
       times a phase factor, since exp(-i*k(Ri*tj-tj)) not 1
       for all pair of {Ri|ti} and {Rj|tj}.

       WILL BE IMPLEMENTED

********************************************************************************
"

i guess now i need some way around this problem.

any help will be highly appreciated.

-- 
*M. Arshad Farhan*
EMMG, Physics Division
PINSTECH, Islamabad
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20160629/ec25977a/attachment.html>


More information about the Wien mailing list