Ba2Ta15O32 Siegrist T, Cava R J, Krajewski J J Materials Research Bulletin 32 (1997) 881-887 Reduced alkaline earth tantalates _database_code_amcsd 0014381 7.773 7.773 35.414 90 90 120 R-3 atom x y z Biso Ba 0 0 .36080 1.20 Ta1 0 0 0 .56 Ta2 .26354 .19279 .265872 .45 Ta3 0 0 .13866 .39 Ta4 .21524 .19221 .467499 .31 O1 .2343 .2071 .5685 .64 O2 .2402 .1661 .8332 .41 O3 0 0 .2372 .3 O4 .2392 .1759 .1043 .75 O5 .2328 .1725 .7067 .73 O6 .2042 -.0104 .0315 .80