Hi. I'm using WIEN2k_14.2 version and have probelm on irrep (irreducible representation) calculation.
My system is CeFe2Al10 with spacegroup #63 (Cmcm).
I implemented scf cycle, with spin-orbit coupling (init_lapw and initso_lapw) & spin non-polarized, and plotted band with bandpath Z-R-S-GAMMA-Z-T-Y-GAMMA. When I tried to !
compile irrep calculation by x -irrep -so -p command (I implemented with parallel job), some of the symmetric points-Z,R,T gives the result like below in case.outputirso_1 file
********************************************************************************
knum = 1 kname= Z
k = 0.000000 0.000000 0.500000
The point group is D2h
8 symmetry operations in 8 classes
Table 23 on page 39 in Koster et al [7]
Table 31.4 on page 247 in Altmann et al [8]
E C2 C2` C2" I IC2 IC2` IC2"
&
nbsp;G1+ A1g 1 1 1 &!
nbsp; 1 1 1 1 1
G2+ B3g 1 -1 1 -1 1 -1 1 -1
G3+ B1g 1 1 -1 -1 1 1 -1 -1
G4+ B2g 1 -1 -1 1 1 -1 -1 1
G1- A1u 1 1 1 1 -1 -1 !
-1 -1
G2- B3u 1 -1 1 -1 -1 1 -1 1
G3- B1u 1 1 -1 -1 -1 -1 1 1
G4- B2u 1 -1 -1 1 -1 1 1 -1
--------------------------------------------------------
G5+ E1/2g 2
0 0 0 2 !
; 0 0 0
G5- E1/2u 2 0 0 0 -2 0 0 0
labeling of IRs can change due to choice of
symmetry axes: G2 <-> G3 <-> G4
Non-symmorphic crystal and k-point at the BZ surface:
IR of the space group for this k-point cannot simpl!
e
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
*********
**************************************************************!
*********
When I take GAMMA-Y-F0-S-GAMMA-Z-T-G0-R-Z bandpath, there was no result like this one in R,Z,T point. I wonder why I have this kind of result in certain bandpath (Z-R-S-GAMMA-Z-T-Y-GAMMA) although the parity or irrep result implemented on symmetric point shouldn't depend on the bandpath. Isn't the latest version of WIEN2k can't implement irrep calculation on Non-symmorphic crystal? Is this structre non-symmorphic crystal? Importantly, why this discrepancy in irrep result happens between two different bandpaths?
Many thanks!
Nam
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