Database of Zeolite Structures
 

Framework Type OFF
Reference Material
  Material Name: Offretite    
 
Chemical Formula:
 
|(Ca,Mg)1.5K (H2O)14 | [Al4Si14O36]-OFF
 
   
Unit Cell:§
 
hexagonal

 P -6 m 2 (# 187)
    a' = 13.2910 Å b' = 13.2910 Å c' = 7.5820 Å  
    α' = 90.000° β' = 90.000° γ' = 120.000°  
   
Framework Density:
 
15.5 T/1000 Å3
 
 
Channels:
 
[001] 12 6.7 x 6.8* <-> [001] 8 3.6 x 4.9**
Dimensionality
  Sorption (molecular cross section > 3.4Å): 3-dimensional
  Topological (pore opening > 6-ring): 3-dimensional
   
References:
  Bennett, J.M. and Gard, J.A.
  "Non-identity of the Zeolites Erionite and Offretite "
Nature , 214, 1005-1006 (1967)
Material name:   Offretite
Chemical formula:   [Al4Si14O36]-OFF
  § Gard, J.A. and Tait, J.M.
  "The crystal structure of the zeolite offretite, K1.1Ca1.1Mg0.7[Si12.8Al5.2O36]·15.2H2O"
Acta Crystallogr., B28, 825-834 (1972)
  Alberti, A., Cruciani, G., Galli, E. and Vezzalini, G.
  "A reexamination of the crystal structure of the zeolite offretite "
Zeolites, 17, 457-461 (1996)
Material name:   Offretite
Chemical formula:   [Al4Si14O36]-OFF
  Mortier, W.J., Pluth, J.J. and Smith, J.V.
  "The crystal structure of dehydrated natural offretite with stacking faults of erionite type"
Z. Kristallogr., 143, 319-332 (1976)
Material name:   Offretite
Chemical formula:   [Al4Si14O36]-OFF
 
 
Name and Code derivation:
    Offretite
  OFF
 
 
§ Chemical Formula and Unit Cell taken from the reference marked with this sign
Limiting Rings
 
12-ring viewed along [001]

8-ring viewed normal to [001]