Pyroxene-ideal
Thompson R M, Downs R T
American Mineralogist 88 (2003) 653-666
Model pyroxenes I: Ideal pyroxene topologies
Pyroxene #14a based on stacking sequence ABABABCABABC
Note: Atoms Mg, Si, and O are assigned to atomic positions just for convenience.
_database_code_amcsd 0003014
19.595917 6 3.4641016 90 90. 90 P2_1/c
atom    x   y   z
SiA  7/48 5/6 2/3
SiB  3/16 1/6 1/3
SiC  5/16 1/6 1/3
SiD 17/48 5/6   0
SiE 25/48 1/3 1/6
SiF  1/48 5/6 1/3
Mg1a 1/12 1/6   0
Mg2a 1/12   0 1/2
Mg1b  .25 2/3 5/6
Mg2b  .25 1/2 1/3
Mg1c 5/12 1/6   0
Mg2c 5/12   0 1/2
O1A  5/24 5/6 2/3
O2A   1/8   0 5/6
O3A   1/8 5/6 1/3
O1B   1/8 1/6 1/3
O2B  5/24   0 1/6
O3B  5/24 1/6 2/3
O1C   3/8 1/6 1/3
O2C  7/24   0 1/2
O3C  7/24 1/6   0
O1D  7/24 5/6   0
O2D   3/8   0 5/6
O3D   3/8 5/6 1/3
O1E 11/24 1/3 1/6
O2E 13/24   0 5/6
O3E 13/24 1/6 1/3
O1F 23/24 5/6 1/3
O2F  1/24   0 1/6
O3F  1/24 5/6 2/3