Database of Zeolite Structures

Framework Type PSI
Volumes and areas calculated from the idealized framework model
Occupiable Volume 274.11 Å3 (3.92 %)  
Accessible Volume 268.82 Å3 (3.84 %)  
Occupiable Area 458.81 Å2 (319.34 m2/g)  
Accessible Area 409.9 Å2 (285.3 m2/g)  
Specific Occupiable Area 655.33 m2/cm3    
Specific Accessible Area 585.47 m2/cm3    
Maximum diameter of a sphere:      
that can be included 5.79 Å
that can diffuse along a:   4.85 Å b:   1.73 Å c:   1.84 Å  

Occupiable volume That portion of the available volume within the cell that can be visited by the center of a (spherical) water molecule (radius = 1.4Å). The available volume is the unit cell volume remaining after the van der Waals atomic sphere volumes are subtracted.
Occupiable area The area of that surface visited by the center of the water molecule.
Accessible volume That portion of the occupiable volume that has continuity between all unit unit cells. Some pores/cavities have windows that are too small to allow the water molecule access, and so represent isolated occupiable regions.
Accessible area The area of that surface visited by the center of the water molecule.
Specific occupiable area Occupiable area per unit volume
Specific accessible area Accessible area per unit volume


These values were calculated by Mike Treacy, Arizona State University, using his codes "TOTOPOL" and "DelaneysDonkey".
see also:
M. D. Foster, I. Rivin, M. M. J. Treacy and O. Delgado Friedrichs,
A geometric solution to the Largest-Free-Sphere problem in zeolite frameworks,
Microporous and Mesoporous Materials, 90 32-38 (2006).