Montebrasite Groat L A, Raudsepp M, Hawthorne F C, Ercit T S, Sherriff B L, Hartman J S American Mineralogist 75 (1990) 992-1008 The amblygonite-montebrasite series: Characterization by single-crystal structure refinement, infrared spectroscopy and multinuclear MAS-NMR spectroscopy sample A-1 _database_code_amcsd 0001323 6.6837 7.7080 6.9671 90.94 117.75 91.36 C-1 atom x y z occ Uiso P -.01496 .34095 .26173 .0059 Al1 0 0 0 .0060 Al2 0 0 .5 .0058 O1 -.3163 .0161 -.1523 .0087 O2 .2981 .0594 .5809 .0090 O3 .1001 -.2224 -.3868 .0080 O4 .0259 .2340 .0980 .0102 OH .0346 .0859 -.2329 .567 .0093 F .0346 .0859 -.2329 .433 .0093 Li1 .08 -.32 .28 .5 .0277 Li2 .05 -.32 .31 .5 .0277