Formula: Mg Si O3
Name: Pyroxene-ideal
Unit cell: 7.393691 6.0 3.4641016 90.0 117.93835 90.0 , V=135.76
Space group: C12/C1 (15)

Thompson R M , Downs R T , American Mineralogist , 88 (2003) p.653-666, Model pyroxenes I: Ideal pyroxene topologies, Pyroxene #1 based on HCP stacking sequence ABAB. Has the bonding topology of, observed HT-C2/c pyroxenes., Note: Atoms Mg, Si, and O are assigned to atomic positions just for convenience.