AM_Pyroxene-ideal_134 Formula: Mg Si O3 Name: Pyroxene-ideal Unit cell: 6.532 6.0 3.464 90.0 90.0 90.0 , V=135.76 Space group: P21CN (33)

Thompson R M , Downs R T , American Mineralogist , 89 (2004) p.614-628, Model pyroxenes II: Structural variation as a function of tetrahedral rotation, model hi-P protopx with, O3A-O3A-O3A angle = 120, O3B-O3B-O3B angle = 240, and model oxygen radius = 1, Note: Atoms Mg, Si, and O are assigned to atomic positions for convenience