Table 2.

Estimated local densities for Si and OW atoms in MCM41 based on the linear extrapolation of ${\rho }_{\alpha \beta }\left(r\right)$ to $r=0$ using the right-hand side of (9). The corresponding confinement lengths, $L_c=1/a$, where the gradient of the fit lines is given as $\frac{3a}{4}$ were determined at the same time. Also shown are the corresponding core densities (for OW) as determined in Section 3.4 from Figure 9, and the bulk atomic number densities for the same atoms. For fitting the O–O and HW–HW distributions it is assumed the local density of the O and HW atoms is exactly twice that of the corresponding Si and OW atoms. The uncertainties are measured by determining the amount of variation in the respective quantity which would be needed to make a discernible change to the fit. The bracketed value for OW at 210 K corresponds to the value for Ice Ih at 273 K.

Atom	Distributions fitted	${\rho }_{\beta }^{(l)}$	Lc	Core	Bulk
		at./Å3	Å	at./Å3	at./Å3
Si	Si–Si, O–O	0.0183(2)	27.2(1)	–	0.0221
OW (298 K)	OW–OW, HW–HW	0.0253(2)	28.2(1)	0.031(1)	0.0334
OW (210 K)	OW–OW, HW–HW	0.0237(2)	30.0(1)	0.027(1)	(0.0307)