AM_Ferrosilite_3
Formula: Si2 Mg.636 Fe1.331 Ca.032 O6
Name: Ferrosilite
Unit cell: 18.371 9.0 5.242 90.0 90.0 90.0 , V=866.71
Space group: PBCA (61)

Smyth J R , American Mineralogist , 58 (1973) p.636-648, An orthopyroxene structure up to 850 C, T = 280 C