Effenbergerite 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 = 150 K _database_code_amcsd 0007203 7.39482 7.39482 15.8504 90 90 90 *P4/ncc .25 -.25 0 atom x y z occ Uiso Ba .25 .75 0 .5 .0483 Sr .25 .75 0 .5 .0483 Cu .25 .25 .0918 .0652 Si .5123 .9335 .15191 .0316 O1 .4538 .9854 .2459 .5 .0816 O2 .7180 .0000 .13343 .0708 O3 .3741 .0239 .08825 .0786