Discrepancy in matrix representations of symmetry between crystal and cartesian coordinates
This is to record what I observed. QE 6.6 is used.
-
For a simple cubic (
ibrav=1
) system, the matrix representations of the symmetry in crystal and cartesian coordinates are not coincide for some symmetry operations like 90 deg rotation or 120 deg rotation.
scf.in and scf.out -
For a hexagonal (
ibrav=4
) system with space group P6_3/mmc (194), the matrix reps. seem to give different space group P6_3/mcm (193). First I run a calculation withspace_group=194
and obtain a list of matrix reps. of symmetry. Then I used matrix reps. in crystal coordinates to check whether they are really belong to space group 194. To do this, IDENTIFY GROUP of Bilbao Crystallographic Server is used. I assumed the matrix applies to the coordinates from the left. If I assume the reverse (i.e. matrix applies from the right) then it gives space group 194. If this is an intended behavior, I think it should be clarified somewhere in the document.
scf.in and scf.out