NPO: Areas and Volumes

Framework Type NPO

Volumes and areas calculated from the idealized framework model
Occupiable Volume		9.19	Å³	(2.87	%)
Accessible Volume		8.97	Å³	(2.80	%)
Occupiable Area		35.52	Å²	(593.35	m²/g)
Accessible Area		32.6	Å²	(544.61	m²/g)
Specific Occupiable Area		1107.67	m²/cm³
Specific Accessible Area		1016.69	m²/cm³
Maximum diameter of a sphere:
	that can be included	4.23	Å
	that can diffuse along	a: 2.08	Å	b: 2.08	Å	c: 3.71	Å

Explanations
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

Credits:
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).