Pigeonite Nestola F, Tribaudino M, Ballaran T B American Mineralogist 89 (2004) 189-196 High pressure behavior, transformation and crystal structure of synthetic iron-free pigeonite Sample: P = 4.5 GPa _database_code_amcsd 0003199 9.523 8.700 5.136 90 107.80 90 P2_1/c atom x y z occ Biso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) MgM2 .2562 .0204 .2179 .85 1.2 .0150 .0158 .0106 .0020 -.0012 .0052 CaM2 .2562 .0204 .2179 .15 1.2 .0150 .0158 .0106 .0020 -.0012 .0052 MgM1 .2514 .6559 .2192 .63 SiTA .0416 .3424 .2866 .54 SiTB .5516 .8381 .2289 .57 O1A .865 .3401 .182 .79 O2A .1194 .5051 .318 .63 O3A .1076 .2756 .603 .87 O1B .3752 .8389 .124 .71 O2B .6321 .9871 .383 1.03 O3B .6086 .6961 .455 .87