AM_Akermanite_20
Formula: Ca2 (Mg.554 Fe.446) Si2 O7
Name: Akermanite
Unit cell: 7.8679 7.8679 5.0144 90.0 90.0 90.0 , V=310.41
Space group: P-421M (113)

Kusaka K , Ohmasa M , Hagiya K , Iishi K , Haga N , Mineralogical Journal , 20 (1998) p.47-58, On variety of the Ca coordination in the incommensurate structure of, synthetic iron-bearing akermanite, Ca2(Mg0.55,Fe0.45)Si2O7, Note: Sample is synthetic, this is the structure obtained from a standard refinement