AM_Heulandite_5 Formula: N2.24 (Si6.803 Al2.197) O22.88 H38.907 Name: Heulandite Unit cell: 17.738 17.974 7.416 90.0 115.91 90.0 , V=2126.73 Space group: C12/M1 (12)

Yang P , Armbruster T , European Journal of Mineralogy , 10 (1998) p.461-471, X-ray single-crystal structure refinement of NH4-exchanged, heulandite at 100 K