AM_Hatrurite Formula: Ca3 Si O4.987 Name: Hatrurite Unit cell: 7.135 7.135 25.586 90.0 90.0 120.0 , V=1128.03 Space group: R3M (160)

Nishi F , Takeuchi Y , Zeitschrift fur Kristallographie , 168 (1984) p.197-212, The rhombohedral structure of tricalcium silicate at 1200 C, Locality: synthetic, Sample: T = 1200 C, Note: cannot reconcile reported structure with reported bond lengths