Wesselsite Knight K S, Henderson C M B European Journal of Mineralogy 19 (2007) 189-200 Structural basis for the anomalous low-temperature thermal expansion behavior of the gillespite-structured phase Ba0.5Sr0.5CuSi4O10 Sample: T = 25 K _database_code_amcsd 0007208 7.39640 7.39640 15.8466 90 90 90 *P4/ncc .25 -.25 0 atom x y z occ Uiso Ba .25 .75 0 .5 .0251 Sr .25 .75 0 .5 .0251 Cu .25 .25 .09136 .0469 Si .5122 .9334 .15173 .0254 O1 .4545 .9840 .2459 .5 .0554 O2 .7177 -.0002 .13312 .0541 O3 .3736 .0234 .08812 .0664