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:
“It is critical vision alone which can mitigate the unimpeded operation of the automatic.”
—Marshall McLuhan (1911–1980)
“Sometimes apparent resemblances of character will bring two men together and for a certain time unite them. But their mistake gradually becomes evident, and they are astonished to find themselves not only far apart, but even repelled, in some sort, at all their points of contact.”
—Sébastien-Roch Nicolas De Chamfort (1741–1794)