Software for analyzing pseudotranslational sublattices (PTSs) in crystal structures is described. This software makes it possible to enumerate triads of reflections, sort them out with respect to different characteristics, calculate linear and angular subcell parameters, and express the sublattice vectors in terms of the initial lattice vectors. The solution to the most widespread problems is illustrated by the example of the well-known [Ru(NH₃)₆]Cl₃ and [CuL](NO₃)(ReO₄) crystal structures (L is 4,6,6-trimethyl-1,9-diamino-3,7-diazanon-3-en) and the structure of mineral iltisite, which is still unknown. In all cases we observed a tendency of crystal structures to have a higher symmetry, which was noted by Academician Belov in his time. “A material that in fact crystallizes in a lower system is nevertheless rather close (in its crystalline form) to numerical relations characteristic of a higher system.” (Belov [1, p. 227])

In this work, the sensor response of MPcF_x (M = Cu, Co, Zn; x = 0, 4, 16) films toward gaseous NH₃ (10–50 ppm) was studied by a chemiresistive method and compared to that of unsubstituted MPc films to reveal the effects of central metals and F-substituents on the sensing properties. A combination of atomic force microscopy and X-ray diffraction techniques have been used to elucidate the structural features of thin MPcF_x films deposited by organic molecular beam deposition. It has been shown that the sensor response of MPcF₄ films to ammonia is noticeably higher than that of MPc films, which is in good correlation with the values of binding energy between the metal phthalocyanine and NH₃ molecules, as calculated by the density functional theory (DFT) method. At the same time, in contrast to the DFT calculations, MPcF₁₆ demonstrated the lesser sensor response compared with MPcF₄, which appeared to be connected with the different structure and morphology of their films. The ZnPcF₄ films were shown to exhibit a sensitivity to ammonia up to concentrations as low as 0.1 ppm, and can be used for the selective detection of ammonia in the presence of some reducing gases and volatile organic compounds. Moreover, the ZnPcF₄ films can be used for the detection of NH₃ in the gas mixture simulating exhaled air (N₂ 76%, O₂ 16%, H₂O 5%, and CO₂ 3%).

A vacuum-insulated tandem accelerator was used to observe in situ blistering during 2-MeV proton irradiation of metallic samples to a fluence of up to 6.7 × 10²⁰ cm⁻². Samples consisting of copper of different purity, tantalum and tantalum-copper compounds were placed on the proton beam path and forced to cool. The surface state of the samples was observed using a charge-coupled device camera with a remote microscope. Thermistors, a pyrometer and an infrared camera were applied to measure the temperature of the samples during irradiation. After irradiation, the samples were analyzed on an X-ray diffractometer, laser and electron microscopes. The present study describes the experiment, presents the results obtained and notes their relevance and significance in the development of a lithium target for an accelerator-based neutron source, for use in boron neutron capture therapy of cancer.

We propose a technique for the refinement of unit cell parameters (UCPs) using a single crystal diffractometer equipped with a flat-panel area detector. The technique is based on choosing Kα₁ components of X-ray radiation when processing diffraction reflections. The capabilities of the technique are demonstrated on [NiEn₃]MoO₄ single crystals. In two independent experiments, the difference between 2θ_exp and 2θ_calc did not exceed 0.02° while the reproducibility of unit cell parameters was at least 0.008 Å.

A technique for the refinement of unit cell parameters using doublet reflections of the external reference is described. The diffraction reflection of the studied crystal is chosen in such a way that it falls within the region between spectral lines K_α1 and K_α2 of the corresponding doublet of the external reference (in this work, a Si reference). The possibilities of this technique are demonstrated on Ge, InSb, and diamond single crystals. It is shown that unit cell parameters can be measured on standard laboratory diffractometers with a relative error less than 5·10^–5.