Akermanite Kusaka K, Hagiya K, Ohmasa M, Okano Y, Mukai M, Iishi K, Haga N Physics and Chemistry of Minerals 28 (2001) 150-166 Determination of structures of Ca2CoSi2O7, Ca2MgSi2O7, and Ca2(Mg.55Fe.45)Si2O7 in incommensurate and normal phases and observation of diffuse streaks at high temperature Sample: T = 513 K Melilite group _database_code_amcsd 0008523 7.8509 7.8509 5.0127 90 90 90 P-42_1m atom x y z Biso Mg 0 0 0 .84 Ca .33205 .16795 .5058 1.48 Si .1398 .3602 .9338 .70 O1 0 .5 .820 1.7 O2 .1404 .3596 .2541 1.75 O3 .0821 .1871 .7872 1.63