Protopyroxene
Yang H, Finger L W, Conrad P G, Prewitt C T, Hazen R M
American Mineralogist 84 (1999) 245-256
A new pyroxene structure at high pressure: Single-crystal X-ray and Raman study
of the Pbcn - P2_1cn phase transition in protopyroxene
Sample at P = 2.03 GPa, (Mg1.54Li.23Sc.23)Si2O6
_database_code_amcsd 0002094
9.2178 8.7039 5.3119  90 90 90 Pbcn
atom     x     y     z occ Biso
Mg1      0 .0976   .75 .77  .60
Sc1      0 .0976   .75 .23  .60
Mg2      0 .2656   .25 .77  .74
Li2      0 .2656   .25 .23  .74
SiA  .2930 .0908 .0743      .49
O1A  .1187 .0921 .0800      .61
O2A  .3740 .2509 .0728      .78
O3A  .3509 .9811 .3051      .64