Austinite

Austinite is a crystal with the chemical formula CaZnAsO₄(OH). What is the space group and Bravais lattice of austinite?

Solution

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<p>Look up austinite online, for instance at: <a href="http://rruff.geo.arizona.edu/AMS/minerals/Austinite">http://rruff.geo.arizona.edu/AMS/minerals/Austinite</a>. In the CIF file it says the space group is symmetry_space_group_name_H-M 'P 21 21 21'. You can either load the CIF file into a page like <a href="http://lampz.tugraz.at/~hadley/ss1/crystalstructure/structures/cif/jsmol.php?zincblende">http://lampz.tugraz.at/~hadley/ss1/crystalstructure/structures/cif/jsmol.php?zincblende</a> (right-click -> File -> open local file ->  Browse -> select file -> load ) and the app will print the space group at the top or look in the list of space group names on WIkipedia <a href="https://en.wikipedia.org/wiki/List_of_space_groups">https://en.wikipedia.org/wiki/List_of_space_groups</a>. The space group is #19. Then use the file <a href="http://lampz.tugraz.at/~hadley/ss1/crystalstructure/sg2bravais.html">Space Group → Bravais lattice</a> to determine the Bravais lattice. The Bravais lattice is simple orthorhombic.</p>