Pyroxene-ideal
Thompson R M, Downs R T
American Mineralogist 89 (2004) 614-628
Model pyroxenes II: Structural variation as a function of tetrahedral rotation
model diopside at 5.3 GPa after Levien and Prewitt (1981)
with O3-O3-O3 angle = 163.6 and model oxygen radius = 1.304
_database_code_amcsd 0003481
9.607 8.939 5.161 90 108.3 90 C2/c
atom     x      y      z
Mg       0  11/12    1/4
Ca       0    .25    1/4
Si   .3083   1/12  .2632
O1   .1333   1/12  .1611
O2   .3667    .25  .3389
O3   .3667  .0208  .0264