Dear all,
I observed something strange in symmetry analysis.
For example, if we run any calculation with space group Pm-3m (#221), all
symmetries are written in the output. I excerpted some of them (see below). I
used qe-6.6.
My question is following. For simple cubic system I expect crystal and
cartesian coordinate can be taken as same if there is no special reason to take
them different. Then why do we have different matrix representations for 90 deg
rotation (isym = 15, 16) and 120 deg rotation (isym = 17) depending on the
coordinate system?
Is it intended or just a kind of bug?
isym = 14 180 deg rotation - cart. axis [0,1,-1]
cryst. s(14) = ( -1 0 0 )
( 0 0 -1 )
( 0 -1 0 )
cart. s(14) = ( -1.0000000 0.0000000 0.0000000 )
( 0.0000000 0.0000000 -1.0000000 )
( 0.0000000 -1.0000000 0.0000000 )
isym = 15 90 deg rotation - cart. axis [-1,0,0]
cryst. s(15) = ( 1 0 0 )
( 0 0 -1 )
( 0 1 0 )
cart. s(15) = ( 1.0000000 0.0000000 0.0000000 )
( 0.0000000 0.0000000 1.0000000 )
( 0.0000000 -1.0000000 0.0000000 )
isym = 16 90 deg rotation - cart. axis [1,0,0]
cryst. s(16) = ( 1 0 0 )
( 0 0 1 )
( 0 -1 0 )
cart. s(16) = ( 1.0000000 0.0000000 0.0000000 )
( 0.0000000 0.0000000 -1.0000000 )
( 0.0000000 1.0000000 0.0000000 )
isym = 17 120 deg rotation - cart. axis [-1,-1,-1]
cryst. s(17) = ( 0 0 1 )
( 1 0 0 )
( 0 1 0 )
cart. s(17) = ( 0.0000000 1.0000000 0.0000000 )
( 0.0000000 0.0000000 1.0000000 )
( 1.0000000 0.0000000 0.0000000 )
Best regards,
============================================
Minkyu Park
Research Institute of Basic Sciences, University of Ulsan,
93, Daehak-ro, Nam-gu, Ulsan, 44610 Republic of Korea
minkyup...@ulsan.ac.kr<mailto:minkyup...@ulsan.ac.kr>
+82-52-259-1473
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