AM_Akermanite_11 Formula: Ca2 Mg Si2 O7 Name: Akermanite Unit cell: 7.7677 7.7677 4.9495 90.0 90.0 90.0 , V=298.64 Space group: P-421M (113)

Yang H , Hazen R M , Downs R T , Finger L W , Physics and Chemistry of Minerals , 24 (1997) p.510-519, Structural change associated with the incommensurate-normal phase transition, in akermanite, Ca2MgSi2O7, at high pressure, Sample: P = 2.78 GPa, Note: O2-z changed to match reported bond lengths