Verfeinerung der Struktur von Malachit, Cu2(OH)2CO3, durch Neutronenbeugung

Abstract

Abstract The crystal structure of malachite is refined (R = 0.021) with the intensity values of 635 independent neutron reflexions from a single crystal, rather free from absorption and extinction. Concerning the structural geometry, no essential deviations occur from the known results of x-ray diffraction. The thermal elongations are generally largest about the normal to the ([unk]01) layers, between which the bonding is relatively weak. In both of the (medium, bent) OH…O hydrogen bonds, the anisotropic thermal parameters, converted according to the riding model, are – with certain restrictions – in agreement with the measured infrared spectrum as well as with frequencies and directions of the proton vibration calculated from the bonding geometry on the basis of a theoretical model.