Material Name:	Chiavennite
	Chemical Formula:	|Ca4 Mn4 (H2O)8 | [Be8Si20O52(OH)8]--CHI
	Unit Cell:	orthorhombic	P n a b (# 60)
		a' = 8.7290 Å	b' = 31.3260 Å	c' = 4.9030 Å
		α' = 90.000°	β' = 90.000°	γ' = 90.000°
		(Relationship to unit cell of Framework Type: a' = -c, b' = b, c' = a)
	Framework Density:	20.9 T/1000 Å3

Channels:

[001] 9 3.9 x 4.3* Dimensionality   Sorption (molecular cross section > 3.4Å): 1-dimensional   Topological (pore opening > 6-ring): 1-dimensional

	References:
		Tazzoli, V., Domeneghetti, M.C., Mazzi, F. and Cannillo, E.
			"The crystal structure of chiavennite"
			Eur. J. Mineral., 7, 1339-1344 (1995)

	Name and Code derivation:
		Chiavennite   -CHI