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 spodumene at 760C after Cameron et al. (1973)
with O3-O3-O3 angle = 186.6 and model oxygen radius = 1.267
_database_code_amcsd 0003488
9.589 8.766 5.061 90 111.7 90 C2/c
atom     x      y      z
Al       0  11/12    1/4
Li       0    .25    1/4
Si   .3081   1/12  .2989
O1   .1339   1/12  .1770
O2   .3661    .25  .3230
O3   .3661 -.0083  .0979