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 = 359.4 K
Melilite group
_database_code_amcsd 0008519
7.8387 7.8387 5.0072 90 90 90 P-42_1m
atom      x      y     z Biso
Mg        0      0     0  .63
Ca   .33205 .16795 .5060 1.17
Si    .1399  .3601 .9338  .51
O1        0     .5  .818  1.5
O2    .1403  .3597 .2545 1.42
O3    .0827  .1864 .7871 1.41