Pyroxene-ideal
Thompson R M, Downs R T
American Mineralogist 88 (2003) 653-666
Model pyroxenes I: Ideal pyroxene topologies
Pyroxene #6 based on stacking sequence ABABACBC
Note: Atoms Mg, Si, and O are assigned to atomic positions just for convenience.
_database_code_amcsd 0003002
13.063945 6 3.4641016 90 90. 90 Pc
atom     x     y   z
SiA  31/32 11/12 1/6
SiB  29/32  5/12   0
Mg1a 13/16  1/12   0
Mg2a 13/16   3/4   0
SiC  23/32  5/12 2/3
SiD  21/32  1/12 1/3
Mg1b  9/16  5/12 1/3
Mg2b  9/16   3/4 1/3
SiE  13/32  7/12 1/2
SiF  15/32  1/12 1/3
Mg1c  5/16  1/12 2/3
Mg2c  5/16   3/4 2/3
SiG   5/32  1/12   0
SiH   7/32  5/12 1/3
Mg1d  1/16  5/12 2/3
Mg2d  1/16   .25 1/6
O1A    7/8 11/12 1/6
O2A      0   3/4   0
O3A      0  1/12   0
O1B      0  5/12   0
O2B    7/8  7/12 1/6
O3B    7/8   3/4 2/3
O1C    5/8  5/12 2/3
O2C    3/4   .25 5/6
O3C    3/4  5/12 1/3
O1D    3/4  1/12 1/3
O2D    5/8   .25 1/6
O3D    5/8 11/12 1/6
O1E    1/2  5/12   0
O2E    3/8   3/4 1/3
O3E    3/8  5/12 1/3
O1F    3/8  1/12 1/3
O2F    1/2   3/4   0
O3F    1/2  1/12   0
O1G    .25  1/12   0
O2G    1/8   3/4 1/3
O3G    1/8  1/12 1/3
O1H    1/8  5/12 1/3
O2H    .25   .25 1/2
O3H    .25  5/12   0