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 = 400 C Locality: Hungary _database_code_amcsd 0018988 6.9897 6.9897 17.574 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 .028 .032 0 .020 .016 0 0 NaA 0 0 0 .071 .028 .032 0 .020 .016 0 0 Al 0 .5 .5 .964 .012 .008 .010 .017 .004 0 0 S 0 0 .30142 .014 .014 0 .015 .007 0 0 O1 0 0 .38341 .024 .029 0 .014 .015 0 0 O2 .21866 -.21866 -.06115 .021 .024 .024 .020 .017 .001 .001 O3 .12616 -.12616 .14040 .017 .013 .013 .024 .005 .002 .002 H .1838 -.1838 .1111 .048