Pyroxene-ideal
Thompson R M, Downs R T
American Mineralogist 88 (2003) 653-666
Model pyroxenes I: Ideal pyroxene topologies
Pyroxene #16 based on stacking sequence ABABACABABAC
Note: Atoms Mg, Si, and O are assigned to atomic positions just for convenience.
_database_code_amcsd 0003018
19.899748 6 3.4641016 90 100.024987862 90 Cc
atom     x    y     z
SiA   1/48 5/12 17/48
SiB   1/16 1/12  1/16
Mg1a   1/8 5/12 19/24
Mg2a   1/8  .25  7/24
SiC   3/16 1/12 25/48
SiD  11/48 5/12 11/48
Mg1b  7/24 1/12 23/24
Mg2b  7/24  .25 11/24
SiE  17/48 7/12 25/48
SiF  19/48 1/12 19/48
Mg1c 11/24 5/12 19/24
Mg2c 11/24  .25  7/24
O1A   1/12 5/12  5/12
O2A      0  3/4     0
O3A      0 5/12     0
O1B      0 1/12     0
O2B   1/12  .25 11/12
O3B   1/12 1/12  5/12
O1C    .25 1/12  7/12
O2C    1/6  .25   2/3
O3C    1/6 1/12   1/6
O1D    1/6 5/12   1/6
O2D    .25  3/4  7/12
O3D    .25 5/12  7/12
O1E   5/12 7/12  7/12
O2E    1/3  3/4   1/3
O3E    1/3 5/12   1/3
O1F    1/3 1/12   1/3
O2F   5/12  .25  7/12
O3F   5/12 1/12  1/12