Gypsum Knight K S, Stretton I C, Schofield P F Physics and Chemistry of Minerals 26 (1999) 477-483 Temperature evolution between 50 K and 320 K of the thermal expansion tensor of gypsum derived from neutron powder diffraction data Sample: T = 320 K _database_code_amcsd 0008228 5.6769 15.2074 6.5277 90 118.494 90 *I2/a .25 .25 .25 atom x y z Ca .5 .0786 .25 S 0 .0787 .75 O1 -.0384 .1326 .5512 O2 .2429 .0215 .8347 Ow .3784 .1825 .4554 D1 .2504 .1615 .5009 D2 .4022 .2435 .4900