Braunite_6 Formula: Mn7 Si O12 Name: Braunite Unit cell: 9.3786 9.3786 18.6234 90.0 90.0 90.0 , V=1638.08 Space group: I41/ACD (142)
Miletich R , Allan D R , Angel R J , Physics and Chemistry of Minerals , 25 (1998) p.183-192, Structural control of polyhedral compression in synthetic braunite,, Mn2+Mn3+6O8SiO4, Sample: P = 2.66 GPa