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 = 500 C Locality: Hungary _database_code_amcsd 0018990 6.9935 6.9935 17.640 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 .033 .029 0 .042 .014 0 0 NaA 0 0 0 .071 .033 .029 0 .042 .014 0 0 Al 0 .5 .5 .932 .026 .011 .013 .054 .005 .001 .001 S 0 0 .3010 .030 .019 0 .051 .009 0 0 O1 0 0 .3827 .041 .035 0 .053 .018 0 0 O2 .2186 -.2186 -.0619 .035 .032 .032 .048 .021 .001 .001 O3 .1266 -.1266 .1403 .034 .016 .016 .067 .007 .001 .001