Group cm

Orbifold notation: *×.
Coxeter notation: [∞⁺,2⁺,∞]
Lattice: rhombic
Point group: D₁
The group cm contains no rotations. It has reflection axes, all parallel. There is at least one glide reflection whose axis is not a reflection axis; it is halfway between two adjacent parallel reflection axes.
This group applies for symmetrically staggered rows (i.e. there is a shift per row of half the translation distance inside the rows) of identical objects, which have a symmetry axis perpendicular to the rows.

Examples of group cm