Pyroxene-ideal
Thompson R M, Downs R T
American Mineralogist 88 (2003) 653-666
Model pyroxenes I: Ideal pyroxene topologies
Pyroxene #3b based on stacking sequence ABABCACABCBC. Ideal analogue of low
clinopyroxene.
Note: Atoms Mg, Si, and O are assigned to atomic positions just for convenience.
_database_code_amcsd 0002999
6.9282032 6 3.4641016 90 109.4712 90 P2_1/c
atom   x   y    z
SiA 1/16 1/3  3/8
SiB 9/16 5/6 5/24
Mg1  .25 2/3  1/6
Mg2  .25   0  1/6
O1A  7/8 1/3  1/4
O1B  3/8 5/6 1/12
O2A  1/8 1/2  1/4
O2B  5/8   0 5/12
O3A  1/8 1/3  3/4
O3B  5/8 2/3 5/12