Pyroxene-ideal
Thompson R M, Downs R T
American Mineralogist 88 (2003) 653-666
Model pyroxenes I: Ideal pyroxene topologies
Pyroxene #4 based on CCP stacking sequence ABCABCABCABC. Ideal analogue of HP-C2/c
pyroxene and eight-coordinaSiEd Mg2-C2/c pyroxene.
Note: Atoms Mg, Si, and O are assigned to atomic positions just for convenience.
_database_code_amcsd 0003000
6.6332495 6.0 3.4641016 90 100.0250 90 C2/c
atom  x     y    z
Si 5/16  1/12 3/16
Mg1   0 11/12  1/4
Mg2   0   .25  1/4
O1  1/8  1/12  1/8
O2  3/8   .25  3/8
O3  3/8  1/12  7/8