Serial reflection conditions

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== Definition ==
== Definition ==
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The serial reflection conditions are the general [[reflection conditions]] due to the presence of screw axes.
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The serial reflection conditions are the general [[reflection conditions]] due to the presence of screw axes. The resulting conditions apply only to onedimensional sets of reflections, ''i.e.'' reciprocal-lattice rows containing the origin (such as ''h''00, 0''k''0, 00''l''). For instance, for a screw axis parallel to [001], the reflection conditions are:
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<table border cellspacing=0 cellpadding=5 align=center>
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<tr>
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<th> type of reflection</th><th>reflection condition</th> <th> screw vector</th><th> screw axis</th> </tr>
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<tr> <td rowspan=2>00''l''</td> <td>''l'' = 2 ''n''</td> <td>'''c'''/2</td><td> 2<sub>1</sub>; 4<sub>2</sub></td></tr>
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<tr>
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<td>''l'' = 4 ''n''</td><td>'''c'''/4</td> <td> 4<sub>1</sub>; 4<sub>3</sub></td></tr>
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<tr> <td rowspan=3>000''l''</td> <td>''l'' = 2 ''n''</td> <td>'''c'''/2</td><td> 6<sub>3</sub> </td></tr>
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<tr>
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<td>''l'' = 3 ''n''</td> <td>'''c'''/3</td><td> 4<sub>1</sub>; 3<sub>1</sub>; 3<sub>2</sub>; 6<sub>2</sub>; 6<sub>4</sub></td></tr>
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<tr>
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<td>''l'' = 6 ''n''</td><td>'''c'''/6</td><td>6<sub>1</sub>;6<sub>5</sub></td/tr>
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</table>
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The serial reflection conditions are listed in Table 2.2.13.2 of ''International Tables of Crystallography, Volume A''.  
==See also ==
==See also ==

Revision as of 07:27, 5 May 2006

Conditions de réflexion sériales (Fr).

Definition

The serial reflection conditions are the general reflection conditions due to the presence of screw axes. The resulting conditions apply only to onedimensional sets of reflections, i.e. reciprocal-lattice rows containing the origin (such as h00, 0k0, 00l). For instance, for a screw axis parallel to [001], the reflection conditions are:

type of reflectionreflection condition screw vector screw axis
00l l = 2 n c/2 21; 42
l = 4 nc/4 41; 43
000l l = 2 n c/2 63
l = 3 n c/3 41; 31; 32; 62; 64
l = 6 nc/661;65

The serial reflection conditions are listed in Table 2.2.13.2 of International Tables of Crystallography, Volume A.

See also

reflection conditions
Section 2.2.13 of International Tables of Crystallography, Volume A