Difference between revisions of "Integral reflection conditions"
From Online Dictionary of Crystallography
BrianMcMahon (talk | contribs) m (Corrected some broken HTML in the table markup) |
BrianMcMahon (talk | contribs) (The selection rules for Obverse and Reverse setting for the Rhombehedrally centered cell were the wrong way round. Email from Alex Hubert; confirmed by Mois Aroyo.) |
||
| Line 36: | Line 36: | ||
<tr align=left> | <tr align=left> | ||
<td> − ''h'' + ''k'' + ''l'' = 3''n''</td> <td> rhombohedrally<br> | <td> − ''h'' + ''k'' + ''l'' = 3''n''</td> <td> rhombohedrally<br> | ||
| − | |||
| − | |||
| − | |||
| − | |||
centred, obverse<br> | centred, obverse<br> | ||
setting (standard)</td> | setting (standard)</td> | ||
| − | </tr> | + | <td rowspan=2>''R'' (hexagonal axes)</td></tr> |
| + | <tr align=left> | ||
| + | <td> ''h'' − ''k'' + ''l'' = 3''n''</td><td> rhombohedrally<br> | ||
| + | centred, reverse<br> | ||
| + | setting </td></tr> | ||
<tr align=left> | <tr align=left> | ||
<td> ''h'' − ''k'' = 3''n''</td> <td>hexagonally centred</td> <td> ''H''</td></tr> | <td> ''h'' − ''k'' = 3''n''</td> <td>hexagonally centred</td> <td> ''H''</td></tr> | ||
Revision as of 12:44, 5 May 2015
Conditions de réflexion intégrales (Fr).
Definition
The integral reflections are the general reflection conditions due to the centring of cells. They are given in the table below:
| Reflection condition |
Centring type of cell | Centring symbol |
|---|---|---|
| None | Primitive | P R (rhombohedral axes) |
| h + k = 2n | C-face centred | C |
| k + l = 2n | A-face centred | A |
| l + h = 2n | B-face centred | B |
| h + k + l = 2n | body centred | I |
| h + k, h + l and k + l = 2n or: | all-face centred | F |
| − h + k + l = 3n | rhombohedrally centred, obverse |
R (hexagonal axes) |
| h − k + l = 3n | rhombohedrally centred, reverse | |
| h − k = 3n | hexagonally centred | H |
See also
Section 2.2.13.1 of International Tables of Crystallography, Volume A