Alunite Zema M, Callegari A M, Tarantino S C, Gasparini E, Ghigna P Mineralogical Magazine 76 (2012) 613-623 Thermal expansion of alunite up to dehydroxylation and collapse of the crystal structure Note: T = 300 C Locality: Hungary _database_code_amcsd 0018987 6.9859 6.9859 17.481 90 90 120 R-3m atom x y z occ Uiso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) KA 0 0 0 .876 .023 .027 0 .017 .013 0 0 NaA 0 0 0 .071 .023 .027 0 .017 .013 0 0 Al 0 .5 .5 .963 .010 .007 .009 .014 .003 0 0 S 0 0 .30179 .012 .012 0 .011 .006 0 0 O1 0 0 .38430 .021 .025 0 .011 .013 0 0 O2 .21854 -.21854 -.06078 .017 .020 .020 .016 .014 0 0 O3 .12611 -.12611 .14039 .015 .011 .011 .020 .005 .002 .002 H .1840 -.1840 .1110 .041