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 calcium cobalt px after Ghose et al. (1987)
with O3-O3-O3 angle = 165.1 and model oxygen radius = 1.325
_database_code_amcsd 0003504
9.785 9.100 5.254 90 108.5 90 C2/c
atom     x      y      z
Co       0  11/12    1/4
Ca       0    .25    1/4
Si   .3083   1/12  .2655
O1   .1334   1/12  .1622
O2   .3666    .25  .3378
O3   .3666  .0189  .0310