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 = 297 K
Melilite group
_database_code_amcsd 0008517
7.8348 7.8348 5.0087 90 90 90 P-42_1m
atom      x     y     z Biso
Mg        0     0     0  .70
Ca   .33180 .1682 .5066 1.38
Si    .1397 .3603 .9350  .61
O1        0    .5  .820  2.1
O2    .1402 .3598 .2551 1.53
O3    .0825 .1870 .7883  1.9