AM_Wohlerite Formula: Na2 Ca4 (Zr Nb) Si4 O17 F H3 Name: Wohlerite Unit cell: 10.8 10.26 7.26 90.0 108.95 90.0 , V=760.87 Space group: P1211 (4)

Shibaeva R I , Belov N V , Doklady Akademii Nauk SSSR , 146 (1963) p.897-900, Crystal structure of wohlerite, Ca2Na(Zr,Nb)[Si2O7](OH)2