spheres related by glide operation
positions following reflection
   and before translation

show glide plane
hide glide plane

view along glide direction
view along glide plane normal

Types of Glide Plane

axial glide (a, b, c)
n-glide
diamond glide (d)

The operation of a glide plane combines a mirror reflection in this plane with a translation in the glide direction. Components of the glide operation must be parallel to the plane. The symbol for a glide plane depends on the glide direction, as follows.

[1] Axial glides involve reflection then translation by half a unit cell along any one of the three axial directions, [100], [010] or [001]. The symbols for axial glides are correspondingly a, b, or c.

[2] An n-glide involves reflection then translation by half a unit cell in two axial directions: (a+b)/2, (a+c)/2, or (b+c)/2. An n-glide in three directions, (a+b+c)/2, is possible only for tetragonal and cubic lattices.

[3] Diamond glides, d, involve reflection then translation by one quarter of a unit cell in two axial directions. This glide operation is named for its presence in the crystal structure of diamond. The translation may be (a+b)/4, (a+c)/4, or (b+c)/4. A d-glide in three directions, (a+b+c)/4, is possible for cubic and tetragonal systems only.

Click and hold the mouse over the CHIME image, then move the mouse to rotate. The glide plane is shown by a pale blue grid. Example unit cells, shown by ochre squares, are shown for axial, n-glide and diamond glide operations. The direction of translation lies within the plane, and is shown in some of the images as a red line.