Richterite
Della Ventura G, Robert J-L, Beny J-M, Raudsepp M, Hawthorne F C
American Mineralogist 78 (1993) 980-987
The OH-F substitution in Ti-rich potassium richterite: Rietveld structure
refinement and FTIR and micro-Raman spectroscopic studies of synthetic
amphiboles in the system K2O-Na2O-CaO-MgO-SiO2-TiO2-H2O-HF
Sample Rich60
Atomic parameters from ICSD
_database_code_amcsd 0001611
10.0427 18.0254 5.2922 90 104.875 90 C2/m
atom     x     y     z occ Biso
O1   .1135 .0887 .2173       .8
O2   .1125   .17 .7254       .8
OH   .1044     0 .7149  .6   .8
F    .1044     0 .7149  .4   .8
O4   .3545 .2467 .7892       .8
O5   .3375 .1285 .0953      1.1
O6   .3375 .1158 .5893      1.1
O7   .3316     0 .3146      1.2
Si1   .278 .0857 .2982       .4
Si2  .2827 .1704 .8111 .88   .4
Ti   .2827 .1704 .8111 .12   .4
Mg1      0 .0906    .5       .6
Mg2      0 .1785     0       .6
Mg3      0     0     0       .6
Na       0 .2763    .5  .5   .9
Ca       0 .2763    .5  .5   .9
K    .0252    .5 .0503  .5  2.3