Search results for "Mirror plane"
showing 4 items of 4 documents
Charoite, as an example of a structure with natural nanotubes
2012
Charoite from the Murun massif in Yakutiya, Russia (Vorob’ev 2008) was investigated using automated electron diffraction tomography (ADT) (Kolb et al. 2007, 2008; Mugnaioli et al. 2010) and precession electron diffraction (PED) (Mugnaioli et al. 2010, 2009), which allowed to determine the structure of charoite for the first time. The structure was solved ab initio in space group P21/m by direct methods using a fully kinematic approach. The least squares refinements with 2878 reflections F(hkl) >4s F converged to unweighted/weighted residuals R 1/wR 2 • 0.173/0.21 (Rozhdestvenskaya et al. 2010).
Dicaesium silver zinc thiocyanate, Cs2[AgZn(SCN)5]
2001
The title compound, dicaesium(I)-μ-thiocyanato-κ2N:S-zinc(II)-tetra-μ-thiocyanato-κ2S:N-argentate(I), crystallizes in the orthorhombic space group Pmn21 and contains units of composition AgZn(SCN)3 lying on a mirror plane and bonded together through Cs+ ions and thiocyanate groups. The crystal studied contained equal numbers of inversion twins.
(Z)-1-Chloro-1-[2-(2-nitrophenyl)hydrazinylidene]propan-2-one
2012
The title molecule, C9H8ClN3O3, lies on a mirror plane. Intramolecular N—H...O and N—H...Cl hydrogen bonds occur. One of the nitro O atoms is disordered (site occupancy ratio = 0.40:0.10).
Evidence of noncentrosymmetry of human tooth hydroxyapatite crystals
2014
Herein, we investigate human single hydroxyapatite crystals (enamel and dentine) by convergent-beam electron diffraction (CBED) and automated electron-diffraction tomography (ADT). The CBED pattern shows the absence of the mirror plane perpendicular to the c axis leading to the P63 space group instead of the P63 /m space group considered for larger-scale crystals, this is confirmed by ADT. This experimental evidence is of prime importance for understanding the morphogenesis and the architectural organization of calcified tissues.