AM_Vuonnemite_1
Formula: Si4 P2 Nb2 Ti2 Na11 O26
Name: Vuonnemite
Unit cell: 5.497 7.163 14.437 92.55 95.3 90.61 , V=565.40
Space group: P-1 (2)

Ercit T S , Cooper M A , Hawthorne F C , The Canadian Mineralogist , 36 (1998) p.1311-1320, The crystal structure of vuonnemite, Na11TiNb2(Si2O7)2(PO4)2O3(F,OH),, a phosphate-bearing sorosilicate of the lomonosovite group, Locality: Lovozero, Kola Peninsula, Russia