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 Rich62
Atomic parameters from ICSD
_database_code_amcsd 0001613
10.0166 18.0189 5.2871 90 104.908 90 C2/m
atom     x     y     z occ Biso
O1   .1104 .0886 .2162       .8
O2   .1168 .1697 .7248       .8
OH   .1025     0 .7164  .2   .8
F    .1025     0 .7164  .8   .8
O4   .3563  .247 .7933       .8
O5   .3361 .1294 .0948      1.1
O6   .3361 .1166 .5897      1.1
O7    .334     0 .3196      1.2
Si1  .2764 .0846 .2985       .4
Si2  .2815 .1704 .8102 .94   .4
Ti   .2815 .1704 .8102 .06   .4
Mg1      0 .0903    .5       .6
Mg2      0 .1796     0       .6
Mg3      0     0     0       .6
Na       0 .2757    .5  .5   .9
Ca       0 .2757    .5  .5   .9
K     .025    .5 .0576  .5  2.3