AM_Heulandite
Formula: (Si13.554 Al4.446) O44.08 Pb2
Name: Heulandite
Unit cell: 17.767 17.917 7.432 90.0 116.33 90.0 , V=2120.39
Space group: C1M1 (8)

Gunter M E , Armbruster T , Kohler T , Knowles C R , American Mineralogist , 79 (1994) p.675-682, Crystal structure and optical properties of Na- and Pb-exchanged, heulandite-group zeolites, Sample: Pb-exchanged, Atomic parameters from ICSD