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Forthcoming article in Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials



Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials publishes scientific articles related to the structural science of compounds and materials in the widest sense. Knowledge of the arrangements of atoms, including their



 



Mean bond-length variations in crystals for ions bonded to oxygen
Variations in mean bond-length are examined in oxide and oxysalt crystals for 55 cation configurations bonded to O2-. Bond-length distortion is confirmed as a statistically-significant causal factor of mean bond-length variation. The assignment of a coordination-based radius to O2- is found not to be supported by experimental data.






Multi-temperature structure of thermoelectric Mg2Si and Mg2Sn
We report accurate structural parameters of Mg2Si and Mg2Sn, which are useful for studies of these promising thermoelectric materials and their solid solutions.



Atomic structures of ternary Yb–Cd–Mg icosahedral quasicrystals and a 1/1 approximant
A systematic study of the structures of ternary icosahedral Yb–Cd–Mg quasicrystals with different Mg contents has been carried out by single-crystal X-ray diffraction; occupational and positional disorder in the resulting structures was compared with that in a Yb–Cd–Mg 1/1 approximant.



X-ray, dielectric, piezoelectric and optical analyses of a new nonlinear optical 8-hy­droxy­quinolinium hydrogen squarate crystal
The structure of a novel nonlinear optical 8-hydroxyquinolinium hydrogen squarate single crystal and the three-dimensional expansion of its supramolecular chain are reported. The Hirshfeld surface of the 8-hy­droxy­quinolinium cation and the hydrogen squarate mono-anion are connected through O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds.



Effect of processing parameters on microstructural properties of lead magnesium niobates
Microstructural analysis of the room-temperature synchrotron X-ray diffraction (XRD) data of lead magnesium niobate samples prepared under different processing conditions has been carried out using the Rietveld method to study the polar nanoregions (R3m phase). This is the minor phase and normally not accessible using laboratory-source XRD data. It is found that the Gaussian component of size broadening is apposite for the polar rhombohedral phase (R3m) and the Lorentzian component of strain broadening is apposite for the paraelectric cubic phase (Pm\overline 3m).



New superprotonic crystals with dynamically disordered hydrogen bonds: cation replacements as the alternative to temperature increase
The single-crystal structure of (K0.43(NH4)0.57)3H(SO4)2 has been determined using X-ray diffraction; its dielectric properties have been studied to define the structural influence on the abnormal physical properties.



The extended Zintl–Klemm concept, ionic strength I and assessment of the relative stability of lattices using the stability enhancement ratio S
Ionic stregth (I) calculations on 25 silicates indicate that the I values of the Zintl polyanions are higher than those of the original compound. The extended Zintl–Klemm concept is reinforced by the application of the thermodynamically related ionic strength, I.



Orientational disorder and phase transitions in ammonium oxo­fluoro­vanadates, (NH4)3VOF5 and (NH4)3VO2F4
The high-temperature elpasolite-like crystal structure of (NH4)3VOF5 with six spatial orientations of the VOF53− octahedron undergoes an order–disorder phase transition with the existence of two octahedral dynamic states at room temperature.



Conformational and structural diversity of iridium di­methyl sulfoxide complexes
Iridium(III) di­methyl sulfoxide complexes, analogues to clinically significant metallodrugs, exhibiting different rotamers in their solid-state structures are investigated. The effect of the amount of the crystallized water and the hydrogen-bonded network in their supramolecular structures on the conformational preferences is studied.



A review of the oxidation–pressure concept (OPC) and extended Zintl–Klemm concept (EZKC), and the emergence of the high-pressure Ni2In-type phase of lithium sulfide (Li2S) rationalized by reference to a newly defined stability enhancement ratio (S)
The Ni2In phase of Li2S (P63/mmc), recently observed at 30 GPa as the final step in the transition antifluorite→anticotunnite→Ni2In, provides evidence of the oxidation–pressure concept, since the [Li2S] subarray of the high-pressure phase of Li2SO4 (Cmcm) is a distortion of the new Li2S phase. Following the extended Zintl–Klemm concept (EZKC), Li2S can be formulated as Li+[LiS]– ≡ Li+[Ψ-BeS] and its usefulness has been enhanced by calculating the values of the ionic strength I. The enhancement factor, S = I[Ψ-BeS]/I[Li2S] = 1.16, denotes increased stability in [Ψ-BeS] as brought about by the EKZC.