Na2Mg6Si8O22(OH)2 Camara F, Oberti R, Iezzi G, Della Ventura G Physics and Chemistry of Minerals 30 (2003) 570-581 The P2_1/m - C2/m phase transition in synthetic amphibole Na NaMg Mg5 Si8 O22 (OH)2: thermodynamic and crystal-chemical evaluation Sample: T = 270 C _database_code_amcsd 0008834 9.723 18.027 5.301 90 102.26 90 C2/m atom x y z occ Biso B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) NaA 0 .5 0 .31 2.27 .0027 .0041 .0027 0 -.0022 0 NaAm .0259 .5 .0914 .25 2.76 .0050 .0036 .0213 0 .0071 0 Mg1 0 .0883 .5 .85 .0031 .0010 .0022 0 .0020 0 Mg2 0 .1795 0 1.11 .0038 .0006 .0114 0 .0022 0 Mg3 0 0 0 .87 .0017 .0004 .0117 0 -.0013 0 Mg4 0 .2620 .5 .595 2.54 .0078 .0030 .0133 0 .0085 0 Na4 0 .2620 .5 .405 2.54 .0078 .0030 .0133 0 .0085 0 Si1 .2810 .0850 .2759 .65 .0025 .0005 .0038 .0002 .0014 0 Si2 .2924 .1707 .7833 .84 .0023 .0007 .0075 -.0002 .0009 .0003 O1 .1126 .0863 .2117 .86 .0016 .0009 .0080 -.0003 .0012 .0001 O2 .1221 .1718 .7191 1.14 .0041 .0011 .0055 -.0004 .0019 .0001 O3 .1088 0 .7058 1.10 .0030 .0007 .0119 0 .0014 0 O4 .3714 .2469 .7798 1.80 .0052 .0011 .0162 -.0012 -.0019 .0004 O5 .3467 .1266 .0588 1.56 .0038 .0018 .0105 .0001 .0028 .0024 O6 .3456 .1191 .5591 1.70 .0032 .0024 .0058 .0006 -.0007 -.0029 O7 .3393 0 .2782 1.64 .0059 .0004 .0230 0 .0049 0 H .195 0 .767 .01