Hexacelsian Kremenovic A, Colomban P, Piriou B, Massiot D, Florian P Journal of Physics and Chemistry of Solids 64 (2003) 2253-2268 Structural and spectroscopic characterization of the quenched hexacelsian _database_code_amcsd 0013253 5.2920 5.2920 15.557 90 90 120 P6_3/mcm atom x y z occ Biso Ba 0 0 0 .99 1.6 Eu 0 0 0 .01 1.6 Si 1/3 2/3 .145 .5 .9 Al 1/3 2/3 .145 .5 .9 O1 1/3 2/3 .25 1.0 O2 .489 0 .104 3.6