Brillouin Zone - Critical Points

Critical Points

Several points of high symmetry are of special interest – these are called critical points.

Symbol Description
Γ Center of the Brillouin zone
Simple cube
M Center of an edge
R Corner point
X Center of a face
Face-centered cubic
K Middle of an edge joining two hexagonal faces
L Center of a hexagonal face
U Middle of an edge joining a hexagonal and a square face
W Corner point
X Center of a square face
Body-centered cubic
H Corner point joining four edges
N Center of a face
P Corner point joining three edges
Hexagonal
A Center of a hexagonal face
H Corner point
K Middle of an edge joining two rectangular faces
L Middle of an edge joining a hexagonal and a rectangular face
M Center of a rectangular face

Other lattices have different types of high-symmetry points. They can be found in the illustrations below.

Read more about this topic:  Brillouin Zone

Famous quotes containing the words critical and/or points:

    The critical period in matrimony is breakfast-time.
    —A.P. (Sir Alan Patrick)

    Only that which points the human spirit beyond its own limitations into what is universally human gives the individual strength superior to his own. Only in suprahuman demands which can hardly be fulfilled do human beings and peoples feel their true and sacred measure.
    Stefan Zweig (18811942)