Computing stoichiometric molecular composition from crystal structures

Gražulis, S.; Merkys, Andrius; Vaitkus, Antanas; Okulič-Kazarinas, Mykolas

doi:10.1107/s1600576714025904

Cited by 174 publications

(120 citation statements)

References 21 publications

(20 reference statements)

Supporting

Mentioning

104

Contrasting

Unclassified

Order By: Relevance

“…The values for the angles and the relevant interplanar distances for α-quartz from the COD database [5], as well as the values obtained from our experimental data using the correlation method, are quoted in Table. These results make it possible to draw the following conclusions. General appearance of the diffraction pattern for α-quartz (a); the same, but scaled up, data (b); and the correlation diffraction pattern of α-quartz (c)…”

Section: Verification Of the Methods On X-ray Diffraction Data Obtainementioning

confidence: 99%

Method of X-Ray Diffraction Data Processing for Multiphase Materials with Low Phase Contents

Scorbun¹,

Gabielkov²,

Zhyganiuk³

et al. 2019

Ukr. J. Phys.

View full text Add to dashboard Cite

Amorphous, glass, and glass-ceramic materials practically always include a significant number (more than eight) of crystalline phases, with the contents of the latter ranging from a few wt.% to several hundredths or tenths of wt.%. The study of such materials using the method of X-ray phase analysis faces difficulties, when determining the phase structure. In this work, we will develop a method for the analysis of the diffraction patterns of such materials, when diffraction patterns include X-ray lines, whose intensities are at the noise level. The identification of lines is based on the search for correlations between the experimental and test lines and the verification of the coincidence making use of statistical methods (computer statistics). The method is tested on the specimens of α-quartz, which are often used as standard ones, and applied to analyze lava-like fuel-containing materials from the destroyed Chornobyl NPP Unit 4. It is shown that the developed technique allows X-ray lines to be identified, if the contents of separate phases is not less than 0.1 wt.%. The method also significantly enhances a capability to determine the phase contents quantitatively on the basis of lines with low intensities.

show abstract

Section: Verification Of the Methods On X-ray Diffraction Data Obtainementioning

confidence: 99%

Method of X-Ray Diffraction Data Processing for Multiphase Materials with Low Phase Contents

Scorbun¹,

Gabielkov²,

Zhyganiuk³

et al. 2019

Ukr. J. Phys.

View full text Add to dashboard Cite

show abstract

“…3a. All reflections can be indexed according to the structure of monoclinic chalcocite (space group P2 1 /c, [34][35][36][37][38][39][40]). The small discrepancies between the Rietveld best fit and the experimental data are compatible with wurtzite structure (space group P 6 3 mc [41]).…”

Section: Powder Scansmentioning

confidence: 99%

Operando SXRD of E-ALD deposited sulphides ultra-thin films: Crystallite strain and size

Giaccherini

Russo

Carlà

et al. 2018

Applied Surface Science

View full text Add to dashboard Cite

a b s t r a c tElectrochemical Atomic Layer Deposition (E-ALD), exploiting surface limited electrodeposition of atomic layers, can easily grow highly ordered ultra-thin films and 2D structures. Among other compounds Cu x Zn y S grown by means of E-ALD on Ag(111) has been found particularly suitable for the solar energy conversion due to its band gap (1.61 eV). However its growth seems to be characterized by a micrometric thread-like structure, probably overgrowing a smooth ultra-thin films. On this ground, a SXRD investigation has been performed, to address the open questions about the structure and the growth of Cu x Zn y S by means of E-ALD. The experiment shows a pseudo single crystal pattern as well as a powder pattern, confirming that part of the sample grows epitaxially on the Ag(111) substrate. The growth of the film was monitored by following the evolution of the Bragg peaks and Debye rings during the E-ALD steps. Breadth and profile analysis of the Bragg peaks lead to a qualitative interpretation of the growth mechanism. This study confirms that Zn lead to the growth of a strained Cu 2 S-like structure, while the growth of the thread-like structure is probably driven by the release of the stress from the epitaxial phase.

show abstract

“…A substructure search in the Crystallography Open Database (COD) for molecules containing the 2‐methoxy‐naphthalene moiety with hydrogen substituents in ortho and ortho’ positions of the methoxy group yielded a total of 174 hits. These 3D structures were super‐imposed and aligned on the aromatic core, as shown in Figure .…”

Section: Figurementioning

confidence: 99%

Existence of a Preferred Orientation for the Methoxy Group on an Extended Aromatic System.

et al. 2018

View full text Add to dashboard Cite

The conformations of a methoxy group introduced on naphthalene in position 2 has been investigated both experimentally (searches in crystallographic data, NOE measurements by NMR) and theoretically with ab initio calculations. While expected at first glance as being equivalent and predicted as such by force field methods, the two conformations where the methoxy is in the plane of the aromatic ring and turned either towards one or the other proton of naphthalene are actually very different in energy : ΔE=1.2 to 1.8 kcal mol−1, a surprisingly high value! The delocalization of the oxygen lone pair on the π‐system of the aromatic ring differs between the two conformers and is proposed to account predominantly for such unexpectedly large ΔE. It is our opinion that given the magnitude of the energies involved, force field methods should be corrected to take into account this conformational effect.

show abstract

Computing stoichiometric molecular composition from crystal structures

Abstract: An algorithm to compute stoichiometrically correct molecular formulae from crystal structures is proposed. The algorithm’s output is suitable for high-volume automated searches in chemical databases and for linking crystallographic and chemical information.

Cited by 174 publications

References 21 publications

Method of X-Ray Diffraction Data Processing for Multiphase Materials with Low Phase Contents

Method of X-Ray Diffraction Data Processing for Multiphase Materials with Low Phase Contents

Operando SXRD of E-ALD deposited sulphides ultra-thin films: Crystallite strain and size

Existence of a Preferred Orientation for the Methoxy Group on an Extended Aromatic System.

Contact Info

Product

Resources

About