Brannockite Armbruster T, Oberhansli R American Mineralogist 73 (1988) 595-600 Crystal chemistry of double-ring silicates: Structures of sugilite and brannockite Sample: small domain _database_code_amcsd 0001159 10.002 10.002 14.263 90 90 120 P6/mcc atom x y z U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) K 0 0 .25 .017 .017 .021 .0085 0 0 Sn 1/3 2/3 .25 .0039 .0039 .0090 .00195 0 0 Li .5 .5 .25 .014 .014 .015 .007 0 0 Si .2384 .3564 .3905 .0033 .0036 .0058 .0017 .0006 .0007 O1 .1313 .3971 0 .020 .020 .008 .008 0 0 O2 .2234 .2800 .1351 .007 .011 .016 .007 .0000 -.001 O3 .1592 .5040 .1733 .005 .005 .008 .001 -.001 -.002