Richterite Della Ventura G, Robert J-L, Raudsepp M, Hawthorne F C American Mineralogist 78 (1993) 633-640 Site occupancies in monoclinic amphiboles: Rietveld structure refinement of synthetic magnesium cobalt potassium richterite Sample: KNi80 Atomic parameters from ICSD _database_code_amcsd 0001578 10.0382 17.954 5.2610 90 104.954 90 C2/m atom x y z occ Biso Si1 .2723 .0851 .3014 0.4 Si2 .2871 .1705 .8067 0.4 Mg1 0 .0899 .5 .1 0.6 Ni1 0 .0899 .5 .9 0.6 Mg2 0 .1785 0 .33 0.6 Ni2 0 .1785 0 .67 0.6 Mg3 0 0 0 .07 0.6 Ni3 0 0 0 .93 0.6 Na 0 .2734 .5 .5 0.9 Ca 0 .2734 .5 .5 0.9 K .0227 .5 .0402 .5 2.3 O1 .1058 .0882 .2131 0.8 O2 .1184 .1711 .7310 0.8 OH3 .1045 0 .7150 0.8 O4 .3590 .2457 .7919 0.8 O5 .3434 .1310 .1050 1.1 O6 .3396 .1154 .6011 1.1 O7 .3322 0 .3046 1.2