0000000000605812

AUTHOR

Ira V. Rozhdestvenskaya

showing 3 related works from this author

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).

PhysicsBoron Nitride; Mirror Plane; Potassium Atom; Apical Oxygen; Kinematic ApproachApical OxygenAnalytical chemistryStructure (category theory)Ab initioengineering.materialLeast squaresPotassium AtomElectron diffractionCharoiteDirect methodsengineeringPrecession electron diffractionBoron NitrideKinematic ApproachBoron Nitride Mirror Plane Potassium Atom Apical Oxygen Kinematic ApproachMirror planeMirror Plane
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The structure of charoite, (K,Sr,Ba,Mn)(15-16)(Ca,Na)(32)[(Si-70(O,OH)(180))](OH,F)(4.0)center dot nH(2)O, solved by conventional and automated elect…

2010

AbstractCharoite, ideally (K,Sr,Ba,Mn)15–16(Ca,Na)32[(Si70(O,OH)180)](OH,F)4.0·nH2O, a rare mineral from the Murun massif in Yakutiya, Russia, was studied using high-resolution transmission electron microscopy, selected-area electron diffraction, X-ray spectroscopy, precession electron diffraction and the newly developed technique of automated electron-diffraction tomography. The structure of charoite (a= 31.96(6) Å,b= 19.64(4) Å,c= 7.09(1) Å, β = 90.0(1)°,V= 4450(24) Å3, space groupP21/m) was solvedab initioby direct methods from 2878 unique observed reflections and refined toR1/wR2= 0.17/0.21. The structure can be visualized as being composed of three different dreier silicate chains: a d…

Charoite010504 meteorology & atmospheric sciencesChemistryAb initioPrecession electron diffraction (PED)engineering.material010502 geochemistry & geophysics01 natural sciencesCrystal structure analysisCrystalAutomated electron diffraction tomography (ADT)CrystallographyElectron diffractionOctahedronGeochemistry and PetrologyCharoiteengineeringAutomated electron diffraction tomography (ADT); Charoite; Crystal structure analysis; Precession electron diffraction (PED)Precession electron diffractionMoleculeSpectroscopy0105 earth and related environmental sciences
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Essential features of the polytypic charoite-96 structure compared to charoite-90

2011

AbstractCharoite, ideally (K,Sr,Ba,Mn)15–16(Ca,Na)32[(Si70(O,OH)180)](OH,F)4·nH20, is a rock-forming mineral from the Murun massif in Yakutia, Sakha Republic, Siberia, Russia, where it occurs in a unique alkaline intrusion. Charoite occurs as four different polytypes, which are commonly intergrown in nanocrystallme fibres. We report the structure of charoite-96(a =32.11(6),b =19.77(4),c =7.23(1) Å, β = 95.85(9)°,V =4565(24) Å3, space groupP21/m),which was solvedab initioby direct methods on the basis of 2676 unique electron diffraction reflections collected by automated diffraction tomography and refined toR1/wR2=0.34/0.37. The structure of charoite-96 is related to that of the charoite-90,…

010504 meteorology & atmospheric sciencesElectron crystallographyAb initiocrystal structure analysisengineering.material010502 geochemistry & geophysicscharoite polytypes01 natural sciencesSilicateNanocrystalline materialchemistry.chemical_compoundCrystallographyelectron crystallographychemistryOctahedronElectron diffractionGeochemistry and PetrologyGroup (periodic table)Charoitecharoite polytypes; crystal structure analysis; electron crystallography; electron diffraction; electron diffraction tomographyengineeringelectron diffractionelectron diffraction tomography0105 earth and related environmental sciences
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