Gypsum Pedersen B F, Semmingsen D Acta Crystallographica B38 (1982) 1074-1077 Neutron diffraction refinement of the structure of gypsum, CaSO4*2H2O Locality: Hampshire, England _database_code_amcsd 0020895 5.679 15.202 6.522 90 118.43 90 *I2/a .25 .25 .25 atom x y z U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) Ca .5 .07967 .25 .0207 .0258 .0195 0 .0081 0 S 0 .07705 .75 .0190 .0204 .0192 0 .0086 0 O1 .96320 .13190 .55047 .0262 .0279 .0243 -.0011 .0123 .0044 O2 .75822 .02226 .66709 .0222 .0270 .0254 -.0046 .0092 .0008 OW .37960 .18212 .45881 .0391 .0294 .0391 .0001 .0253 -.0038 H1 .25112 .16158 .50372 .0599 .0464 .0632 -.0012 .0432 .0018 H2 .40458 .24275 .49217 .0596 .0383 .0714 -.0039 .0384 -.0085