https://dictionary.iucr.org/index.php?action=history&feed=atom&title=Orthohexagonal 2026-07-21T14:08:12Z Revision history for this page on the wiki MediaWiki 1.30.0 https://dictionary.iucr.org/index.php?title=Orthohexagonal&diff=4715&oldid=prev 2018-02-02T16:42:57Z

<p>Created page with &quot;&lt;font color=&quot;blue&quot;&gt;Orthohexagonal&lt;/font&gt; (&#039;&#039;Fr&#039;&#039;). &lt;font color=&quot;red&quot;&gt;Orthohexagonalen&lt;/font&gt; (&#039;&#039;Ge&#039;&#039;). &lt;font color=&quot;black&quot;&gt;Ortoesagonale&lt;/font&gt; (&#039;&#039;It&#039;&#039;). &lt;font color=&quot;purple&quot;&gt;直...&quot;</p> <p><b>New page</b></p><div>&lt;font color=&quot;blue&quot;&gt;Orthohexagonal&lt;/font&gt; (''Fr''). &lt;font color=&quot;red&quot;&gt;Orthohexagonalen&lt;/font&gt; (''Ge''). &lt;font color=&quot;black&quot;&gt;Ortoesagonale&lt;/font&gt; (''It''). &lt;font color=&quot;purple&quot;&gt;直方六方&lt;/font&gt; (''Ja''). &lt;font color=&quot;green&quot;&gt;Ortohexagonal&lt;/font&gt; (''Sp''). <br /> <br /> <br /> The hexagonal lattice is frequently referred to an orthorhombic ''C''-centred cell called '''orthohexagonal''', whose volume is twice that of the [[conventional cell|conventional]] ''P'' cell. Three choices of the orthohexagonal cell are possible:<br /> <br /> * ''C''&lt;sub&gt;1&lt;/sub&gt;, basis vectors change '''a''', '''a'''+2'''b''', '''c''';<br /> * ''C''&lt;sub&gt;2&lt;/sub&gt;, basis vectors change '''a'''+'''b''', -'''a'''+'''b''', '''c''';<br /> * ''C''&lt;sub&gt;3&lt;/sub&gt;, basis vectors change '''b''', -2'''a'''-'''b''', '''c'''.<br /> <br /> The hexagonal symmetry is reflected in the metric specialisation of the orthohexagonal cell, which has ''b'' = ''a''3&lt;sup&gt;1/2&lt;/sup&gt;. As a consequence, an orthorhombic crystal with conventional cell of type ''oC'' and ''b'' = ''a'' ratio close to 3&lt;sup&gt;1/2&lt;/sup&gt; has a [[Pseudo symmetry|pseudo]]-hexagonal lattice.<br /> <br /> ===See also===<br /> * Chapter 1.5 of ''International Tables for Crystallography'', ''Volume A'', 6th edition<br /> <br /> [[Category:Fundamental crystallography]]</div>

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