AM_Pyroxene-ideal_2 Formula: Si Mg O3 Name: Pyroxene-ideal Unit cell: 6.6332498 6.0 3.4641016 90.0 100.02499 90.0 , V=135.76 Space group: P12/C1 (13)

Thompson R M , Downs R T , American Mineralogist , 88 (2003) p.653-666, Model pyroxenes I: Ideal pyroxene topologies, Pyroxene #3a based on stacking sequence ABABCACABCBC, Note: Atoms Mg, Si, and O are assigned to atomic positions just for convenience.