View source for Integral reflection conditions

<Font color="blue"> Conditions de réflexion intégrales</Font> (''Fr''). 

== Definition ==

The integral reflections are the general [[reflection conditions]] due to the centring of cells. They are given in the table below:

<table border cellspacing=0 cellpadding=5 align=center>
<caption align=top> '''Integral reflection conditions for centred lattices.''' </caption>
<tr align=left>
<th> Reflection<br> condition </th>
<th> Centring type of cell </th>
<th>Centring symbol</th>
</tr>
<tr align=left>
<td>None</td> <td> Primitive</td> <td> ''P''<br>
''R'' (rhombohedral axes)</td>
</tr>
<tr align=left>
<td>''h'' + ''k'' = 2''n''</td> <td>''C''-face centred</td> <td>''C''</td>
</tr>
<tr align=left>
<td>''k'' + ''l'' = 2''n''</td> <td>''A''-face centred</td> <td>''A''</td>
</tr>
<tr align=left>
<td>''l'' + ''h'' = 2''n''</td> <td>''B''-face centred</td> <td>''B''</td>
</tr>
<tr align=left>
<td>''h'' + ''k'' + ''l'' = 2''n''</td> <td>body centred</td> <td>''I''</td>
</tr>
<tr align=left>
<td>''h'' + ''k'', ''h'' + ''l'' and<br> 
''k'' + ''l'' = 2''n'' or:<br>
''h'', ''k'', ''l'' all odd or all<br>
even (‘unmixed’)</td> <td>all-face centred</td> <td> ''F''</td>
</tr>
<tr align=left>
<td> &minus; ''h'' + ''k'' + ''l'' = 3''n''</td> <td> rhombohedrally<br>
centred, obverse<br>
setting (standard)</td>
<td rowspan=2>''R'' (hexagonal axes)</td></tr>
<tr align=left>
<td> ''h'' &minus; ''k'' + ''l'' = 3''n''</td><td> rhombohedrally<br>
centred, reverse<br>
setting </td></tr>
<tr align=left>
<td> ''h'' &minus; ''k'' = 3''n''</td> <td>hexagonally centred</td> <td> ''H''</td></tr>
</table>

==See also ==
*Section 2.1.3.13 of ''International Tables of Crystallography, Volume A'', 6<sup>th</sup> edition

[[Category:X-rays]]<br>