AM_Jonesite Formula: Ba4 K1.6 Na.4 Ti4 Si10 Al2 O41.02 H22 Name: Jonesite Unit cell: 10.618 25.918 8.6945 90.0 127.633 90.0 , V=1894.87 Space group: P121/M1 (11)

Krivovichev S V , Armbruster T , American Mineralogist , 89 (2004) p.314-318, The crystal structure of jonesite, Ba2(K,Na)[Ti2(Si5Al)O18(H2O)](H2O)n:, A first example of titanosilicate with porous double layers