Hydrogen Atom Positions in Kaolinite by Neutron Profile Refinement
نویسندگان
چکیده
-A structure refinement of kaolinite made using the Rietveld neutron profile refinement technique has given non-hydrogen atom positions which were not significantly different from those given by B. B. Zvyagin in i960. All of the hydrogen atoms have been located; the three inner-surface hydrogen atoms are involved in interlayer hydrogen bonds with lengths of 2.95(4), 2.95(4), and 3.06(4) ]k with O-H . . . O angles of 168(4) ~ 144(4) ~ and 146(4) ~ respectively. The inner hydrogen atom is located in a position consistent with that found earlier in dickite and muscovite which are the only dioctahedral layer silicates studied by neutron diffraction to date. The O-H vector makes an angle of 34 ~ with the (001) plane, away from the octahedral sheet, and the projection of the vector on to (001) is at ~30 ~ to the b axis. Key Words--Crystal structure, Hydrogen, Kaolinite, Neutron profile refinement, O-H vector, Rietveld method.
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