An Orthorhombic Modification of KCoPO Stabilized under Hydrothermal Conditions: Crystal Chemistry and Magnetic Behavior.

A novel modification of the KCoPO, δ-phase has been prepared by hydrothermal synthesis at 553 K. The compound crystallizes in the orthorhombic system with the unit-cell parameters = 8.5031(8), = 10.

Fine details of crystal structure and atomic vibrations in YbB with a metal-insulator transition.

The crystal structure of single-crystal Kondo insulator YbB was studied at nine temperatures in the range 85-293 K based on X-ray diffraction data. Very weak Jahn-Teller distortions of the cubic lattice were detected at all temperatures, but did not require a revision of the structural model. Heat capacity and electrical conductivity of YbB single crystals were studied in the temperature range 1.

A commensurately modulated crystal structure and the physical properties of a novel polymorph of the caesium manganese phosphate CsMnPO.

A novel modification of the CsMnPO β-phase was achieved by hydrothermal synthesis at 553 K. The compound crystallizes in the monoclinic system with the basic unit-cell parameters a = 11.0699 (4), b = 11.

Characteristic features of polytypism in compounds with the LaWO-type structure.

Crystals with the LaWO-type structure (6H and 5H polytypes) were obtained by a self-flux method from high-temperature solutions. Some of the crystal samples were studied by single-crystal X-ray structure analysis. The diffraction patterns indicated that two phases co-exist in each sample.

The lower symmetry electron-density distribution and the charge transport anisotropy in cubic dodecaboride LuB.

High-quality single crystals of LuB are grown using the induction zone melting method. The x-ray data are collected at temperatures 293, 135, 95, 50 K. The crystal structure of LuB can be refined with record low R-factor in the cubic Fm [Formula: see text] m symmetry group despite reiterated observations of the cubic symmetry distortions both in the unit-cell values and in the physical properties.

Incommensurately modulated twin structure of nyerereite NaKCa(CO).

The incommensurately modulated twin structure of nyerereite NaKCa(CO) has been first determined in the (3 + 1)-dimensional symmetry group Cmcm(α00)00s with modulation vector q = 0.383a*. Unit-cell values are a = 5.

Incommensurate modulation and thermal expansion of Sr3B(2 + x)Si(1 - x)O(8 - x/2) solid solutions.

Crystal structures of Sr3B(2 + x)Si(1 - x)O(8 - x/2) solid solutions with nominal compositions x = 0.28, 0.53, 0.

Modulated structure of Lu4AlCu2B9O23 from low-temperature single-crystal X-ray data.

A second-order phase transition with both displacive and disorder mechanisms was discovered in Lu4AlCu2B9O23 using single-crystal X-ray diffraction techniques by cooling down the sample to 110 K. Low-temperature structure modulations are mainly associated with Cu atoms surrounded by O atoms. The fivefold asymmetric environment leads to a special copper position splitting into a pair of general ones so that four O atoms coordinate each of them.

Synthesis, composition, and structure of sillenite-type solid solutions in the Bi2O3-SiO2-MnO2 system.

Individual compounds and solid solutions are obtained under hydrothermal conditions in the Bi(2)O(3)-SiO(2)-MnO(2) system in the form of faceted crystals and epitaxial films on the Bi(24)Si(2)O(40) substrate. The crystals have the shape of a cube (for the molar ratio of the starting components Na(2)SiO(3)·9H(2)O:Mn(NO(3))(2)·6H(2)O > 1), a tetrahedron (for Na(2)SiO(3)·9H(2)O:Mn(NO(3))(2)·6H(2)O < 1), or a tetrahedron-cube combination (for Na(2)SiO(3)·9H(2)O:Mn(NO(3))(2)·6H(2)O = 1). Crystal-chemical analysis based on the data of single-crystal and powder X-ray diffraction, IR spectra, and the results of calculation of the local balance by the bond-valence method reveals formation of the Bi(24)(Si(4+),Mn(4+))(2)O(40) phases, which probably include Mn(5+) ions (epitaxial films), as well as the Bi(24)(Si(4+),Bi(3+),Mn(4+))(2)O(40) and Bi(24)(Si(4+),Mn(4+))(2)O(40) phases in the (1 - x)Bi(3+)(24)Si(4+)(2)O(40) - x(Bi(3+)(24)Mn(4+)(2)O(40)) system and the Bi(24)(Bi(3+),Mn(4+))(2)O(40) phase in the (1 - x)Bi(3+)(24)Bi(3+)(2)(O(39)ⁱ(1)) - x(Bi(3+)(24)Mn(4+)(2)O(40)) system.

Energetic materials: alpha-NTO crystallizes as a four-component triclinic twin.

The prevalent polymorph of the energetic material 5-nitro-2,4-dihydro-1,2,4,-triazol-3-one, alpha-NTO, crystallizes as a four-component twin with triclinic symmetry (space group P\bar 1). All crystals under investigation were fourlings, i.e.