Structure-forming Components Research Articles

PHASE FORMATION IN ALKALINE TITANOSILICATE SYSTEMS DURING HYDROTHERMAL SYNTHESIS

The investigations in the polycomponent high alkaline systems – TiO2–H2SO4–Na2SiO3–NaOH–H2O and TiO2–H2SO4–(NH4)2SO4–Na2SiO3–NaOH–H2O under hydrothermal synthesis conditions have been carried out to provide new products with the given technical properties. It has been shown that by directed selection of structure-forming components, in particular titanium compounds, together with optimal parameters of hydrothermal treatment of the obtained precursor, it is possible to form compounds with the given phase and chemical composition, morphology and particle size. It was found that the rate of structural transformations during synthesis depends on the phase composition of titanosilicate precursors. During their hydrothermal treatment, alkaline and thermal hydrolysis with subsequent dehydration of hydrolyzed phases of titanium (IV) and silicon take place. The process is accompanied by localization of free bonds providing formation of Ti–O–Si–O-bridges and their subsequent transformation into structured new formations.

Food resources in food system technology: Bifunctional food system technology based on pickering emulsions

The development of domestically generated food additives based on eco-technologies with specified functionaltechnological and bioactive qualities is now a significant focus of contemporary study. Pickering emulsions are more stable both physically and chemically, making them a highly promising method of introducing biologically active chemicals into the body. The purpose of this research was to determine if ultrasound could be used to create a bioactive colloidal Pickering emulsion system using flax cellulose or brown algal polysaccharides as a stabilizer. Pickering emulsions stabilized with fucoidan, sodium alginate, or flax cellulose, based on a lipid fraction of sunflower oil and cinnamon oil blend, or a lipid fraction of linseed oil, were applied to the subjects, who were then subjected to ultrasound treatment at 630W/l for 16 min (4 min on, 3 min off) at a controlled temperature of 50°C. The results obtained demonstrate the effectiveness of using ultrasonic exposure to create bioactive Pickering emulsion colloidal systems. Fucoidan stabilizes pickering emulsion, with the highest AOA values (5.120±0.005 DPPH, %) and a rise in AOA values in linseed oil-based emulsion samples from 30% to 100% in comparison to emulsion samples based on a blend of lipid phases. The viscoelastic characteristics of Pickering emulsions with various oil fractions vary dramatically for the integrated structure-forming components.

Behavior of Glass-like and Mineral-like Phosphate Compounds with an Immobilized Chloride Mixture in Hydrogen Peroxide Solutions

A new type of high-level waste (HLW) is generated during pyrochemical reprocessing of mixed nitride spent uranium–plutonium nuclear fuel. Such waste is a spent electrolyte, which is a mixture of chloride salts containing approximately 25.7 wt.% LiCl + 31.6 wt.% KCl + 4.1 wt.% CsCl + 5.1 wt.% BaCl2 + 3.8 wt.% SrCl2 + 29.7 wt.% LaCl3, and its immobilization in reliable matrices is an actual radiochemical problem. The structure and hydrolytic stability of sodium aluminoironphosphate (NAFP) glass and a low-temperature mineral-like magnesium potassium phosphate (MPP) matrix, which are promising for spent electrolyte immobilization in the presence of hydrogen peroxide solutions simulating natural water radiolysis products, were studied in this work. The structure of the samples was studied using the SEM-EDS method. It was shown that the initial samples of NAFP glass after leaching in hydrogen peroxide solutions are prone to precipitation of crystalline phases on the surface, which are mainly represented by a mixture of sodium–iron–aluminum pyrophosphates. It was established that the leaching rate of structure-forming components of NAFP and MPP matrices generally increase, but remain at a low level, meeting modern requirements for HLW immobilization. This confirms the effectiveness of the studied matrices for the industrial use of the spent electrolyte.

Pulse flaking: Opportunities and challenges, a review.

Pulses provide economic and health benefits to people in many countries around the world; however, their adoption in western diets, particularly in processed and formulated foods, is limited. One strategy to increase the level of pulses in western diets is to improve pulse accessibility to the ready-to-eat (RTE) food market sector. Pulses have compositional and structural differences when compared to cereals and behave differently during processing. While there have been numerous studies on pulses processed using traditional processing methods, there are limited studies describing processing of pulses as a major ingredient in RTE forms such as flakes. To understand the full processing potential of pulses, systematic studies are required using commercial-scale RTE pilot processing equipment coupled with fundamental property determination techniques to evaluate the effects of processing and pulse material on pulse flake attributes. In-depth studies of pulse properties and their processability are likely to result in the production of high-quality pulse-based foods with superior health benefits. This review explores the current and potential opportunities for processing pulses with a focus on flake products. The roles of pulse type and major structure-forming components such as fiber, carbohydrates, and proteins on end-product quality of processed pulses are discussed.

FEATURES OF THE FORMATION OF THE STRUCTURE OF A CEMENTLESS MATRIX COMPOSITE BASED ON MECHANICALLY ACTIVATED TECHNOGENIC RAW MATERIALS

The creation of composite materials using mechanically activated technogenic raw materials is relevant today as part of a large-scale task of construction and technological utilization of technogenic formations. The change in the crystal structure using mechanochemistry increases the activity of technogenic products: the number of coagulation contacts of dissimilar particles increases, increases the plastic strength of the hardening mixture, formation of hydration products is accelerated. The article is devoted to the study of the mechanism of structural and rheological transformations of a cementless hardening system based on activated steelmaking. Steel melting slags were used as raw materials - energy-saturated large-capacity waste of the West-Siberian Metallurgical Combine (Novokuznetsk). As components - activators - waste from the coal industry of the «Abashevskaya» mine (Novokuznetsk) - burnt rocks with heaps and slimes, obtained by neutralization of spent acid battery electrolytes with lime batteries for industrial vehicles. Based on used mechanically activated technogenic raw materials the binder composite material of the matrix structure is obtained. To assess structural and material changes in the hardening system comprehensive physical and chemical studies were carried out: IR - spectroscopy, thermogravimetric and x-ray phase analysis. Electron microscopy investigated the structure of the stone. It was found that the matrix structure of the composite material is a dispersion medium - matrix of dense fine-grained masses calcium sulfate hydrate; dispersed phase from lamellar crystals of quartz and magnesium oxide, and tubular crystals of calcium orthosilicate; and transitional interfacial layer from structured grains of calcium hydrosulfoaluminate. In the process of forming the structure interdependence of phases from each other was accompanied by a sequential transition of some types of structures to others: coagulation→ crystallization- condensation→ crystallization. The article presents the results of the self-organization of the structure, the interaction of oxide systems in the process of hydration is considered, major mineral neoplasms are established, possessing astringent properties and providing strong bonds between structure-forming components.

Allegory as A Linguistic Technique in The Tatar Poetry in the 1920s-1950s

The article concentrates on studying one of the linguistic techniques called allusion technique in Tatar poetry at the background of traditional symbols semantic transformation in Tatar poetry in the 1920s-1950s. While exploring the topic, it is argued that Tatar poets turned symbol images traditional for the national literature into spokesmen for the anti-ideological position. The objective of the study is to explore the allusion technique via a prism of image symbols crosscutting for the national literature as a system of nominations based on Tatar poetry in the 1920-1950s. The scientific novelty is determined by a different approach to exploring the allusion technique: the study focuses on applying the symbol as a structure-forming component. Under the review, namely, symbols are proved to act as structure-forming components and are perceived as a possibility to change artistic paradigms, update an ideological and philosophical depth, and ambiguity. It also provides a possibility to double read the text and national traditions of Tatar poetry.

Arabic Manuscript Book Traditions: Script, Space Arrangement of the Text and Bibliographical Description

The article deals with the phenomenon of medieval Arabic manuscript book or a book written in Arabic script in non-Arabic language. Despite the large number of works where this phenomenon was analyzed, their authors did not provide a clear list of the criteria, which are specific to the Arabic manuscript book tradition in comparison to other medieval manuscript traditions of the West and East. Methodologically, the work is based on the principles of the “immanent analysis” of the phenomenon developed by the Russian and Soviet philological schools at the beginning of the last century in relation to the analysis of literary works. The authors of this article came to the conclusion that the structure-forming components of the phenomenon of the Arabic medieval manuscript book were as follows: 1) the Arabic script, as well as 2) the architectonics of the text of the Arabic manuscript book and 3) the specific features of the Arabic bibliographic description. The authors believe that these three components identified the Arabic (arabographic) handwritten book throughout its existence: from the 9th century AD to the present and from Eastern Europe to Indonesia. The results allow us to clearly understand what distinguished a book belonging to the Arabic manuscript tradition from manuscript books that were transcribed at the same time and in the same region, such as Coptic or Syriac.

New Thermoplastic Damping Polymeric Materials Based on Ethylene-Vinyl Acetate

This article is devoted to the problem of working out of damping polymer materials which are effective in the wide temperature and frequency range. In the modern world, work is being carried out to create damping polymer composite materials (DPM) from which it is possible to manufacture protective elements and parts of engineering structures of reduced vibration excitability. Existing DPM have a narrow temperature range, within which effective vibration absorption is observed, moreover, most of them go through a vulcanization stage, which increases the cost of the final product, has a harmful effect on environment and allows limited recycling of waste. One of the ways to solve this problem is to replace traditional rubber vibration-absorbing materials with thermo-elastoplasts (TEP). The most promising polymer for TEP is ethylene vinyl acetate (EVA), which has high damping properties, oil resistance and relative incombustibility. In this regard, experimental studies were conducted to establish the patterns of influence of the type and concentration of structure-forming components (plasticizers, fillers, modifiers) on the dynamic mechanical properties of TEP based on EVA in order to develop a new DPM effective in a wide temperature range. The leading method to investigate this problem is a method of dynamic mechanical analysis which allows to get information about changes of mechanical characteristics under mechanical load and controlled temperature and frequency. With the help of detected patterns it was possible to determine type of plasticizer which significantly decreases glass temperature of EVA. The percentage ratio of EVA/plasticizer system is stated, and the type of plasticizer at which the maximum of mechanical losses takes over greater values is accordingly detected. It is revealed, that to work out DPM on EVA basis, which are effective in wide temperature range it is more preferable to add not less than 40 % on volume basis inert fillers, such as talc or mica with addition of 5-10 % of carbon as the hardening additive. The kind of resin improving damping properties and raising rigidity of composites on EVA basis is defined. On the basis of the research, a material was developed which has the following properties: the maximum value of tan δ is at least 0.45 at a temperature of plus 5�C (oscillation frequency 10 Hz); width of the temperature interval within which tan δ is not less than 0.3 from minus 40 to plus 50�С (oscillation frequency 10 Hz); conditional tensile strength of not less than 10 kg/cm2, cold resistance up to minus 50�C.

МОДЕЛЬ РОЗВИТКУ УПРАВЛІНСЬКОЇ КОМПЕТЕНТНОСТІ МАЙБУТНІХ ОФІЦЕРІВ ПОЛІЦІЇ

The purpose of the article is to substantiate the model of development of managerial competence of future officers of the National Police of Ukraine in the process of professional training on the basis of subject-active and competence approaches.It is determined that the model of development of managerial competence is based on the ratio of the block of professional competencies, which focuses on the managerial functions of the police officer, and the block of managerial competence, composed of psychological components (motivational, cognitive, emotional-volitional, operative-active, personal and reflexive). The model will be able to reflect the specifics of its formation in the process of professional training.The scientific novelty of the research stands in the fact that a model of development of managerial competence of future police officers is developed and substantiated for the first time. It is considered as the integration of its structure-forming components: motivational, emotional-volitional, cognitive, operative-active, personal and reflexive components as well as functionally forming components: goal-motivational, substantive, procedural, control-corrective and effective.The practical significance of the results of the study is reflected in the substantiation of the psychological conditions and criteria of the development of psychological components of the managerial competence of future police officers, which is the basis of psycho diagnostic apparatus of determining its current status. Empirical verification of the model will allow determining the level of the formation of professional skills among future officers of the National Police of Ukraine for professional and managerial activity and contribution to its productive development.Thus, as a result of the theoretical analysis, the model of development of managerial competence of future police officers is developed, which is one of the necessary steps for differential diagnosis and development of its psychological components in the process of professional training. The following elements were singled out in the model: the block of managerial competence, the block of managerial adequacy, the block vocational training. The discrepancy between the requirements of professional activity to the personal qualities of the manager (the block of managerial competence) and the real level of cadets' readiness for it (the block of managerial adequacy) is the basis for the psychological and pedagogical influence on the personality of the police officer in the educational process of the university (block of professional training).The prospect of further scientific research is to carry out an experimental verification of the proposed model of development of managerial competence among future police officers in the process of training in the institutions of the Ministry of Internal Affairs of Ukraine.

Development of formulations for emulsions and dry mixes for production of semi-finished products using additive technologies

Study of possibilities of using various types of raw materials as fillers for food 3D printers is relevant for development of additive technologies in the field of food production. Currently, the properties are studied to the greatest extent and the ingredients are widely used for confectionery production in the world and, at the same time, the process properties of raw materials of animal origin, in particular meat raw material, as one of the main sources of protein are of greater interest. Process capabilities of meat raw material were studied for this purpose for formulating emulsions or mixtures suitable for use as a raw material for food 3D printer. Formulations of emulsions and dry mixes are developed based on broiler chicken meat, as well as combinations of broiler chicken meat and pork, pork and beef (ratio 1 : 1) for manufacture of semi-finished products, as well as production technologies. It was determined that it is advisable to add structure-forming components to formulations of emulsions in a dry form, which provides improved functional-and-process and structural-and-mechanical indicators in comparison with hydrated and gel forms. It was determined that 15% of hydrolyzed connective tissue or 10 % of hydrolyzed pork skin can reduce the level of structure-forming components in emulsion formulations, and also has a positive effect on reducing the cost price of emulsions while maintaining rational functional-and-process and structural-and-mechanical parameters. It has been revealed that adding 6-12 % of WPS-UF-80, 5-10 % of dry whey or 4-8 % of fat free milk powder into emulsion formulations allows reducing the level of structure-forming ingredients in the formulations. These mixtures and emulsions used as raw materials for food 3D printers will ensure production of innovative group of meat products using additive technologies in the Republic of Belarus.

In Ukrainian

Templated sol-gel synthesis of MCM-41‑type mesoporous silicas was realized in the presence of azo dyes (alizarin yellow and methyl red) as co-templates and silanes obtained on their basis as structure-forming components. It has been found from the results of low-temperature adsorption-desorption of nitrogen that using of azo dyes and dye-containing silanes in sol-gel synthesis leads to the substantial increase of surface area and total pore volume, and decrease of pore diameter of obtained mesoporous organosilicas. The X-ray diffraction analysis proved formation of hexagonally arranged structure of mesopores in synthesized organosilicas. It has been demonstrated due to visualization of mesoporous structure by transmission electron microscopy that all synthesized materials have hexagonally arranged structure of cylindrical pores, entrances to which are oriented outside of particles that provide accessibility of functional groups for sorbate molecules. Obtained organosilicas of MCM-41 type were used in study of dyes sorption from diluted phosphate buffer solutions as dependent on their equilibrium concentration, pH of medium, and duration of contact. It has been found that the most efficient sorption of alizarin yellow takes place at рН ~ 3 and methyl red at рН = 2.5-5.0. Analysis of kinetic curves carried out using Lagergren, Ho‑McKey, and Weber-Morris models has shown that process of azo dyes sorption by organosilicas is described by kinetic model of pseudo‑second order. The parameters of equilibrium sorption of alizarin yellow and methyl red on organosilicas of MCM‑41 type were calculated using Langmuir, Freundlich, Redlich‑Peterson, and Brunauer‑Emmett‑Teller models. Sorption of a number of acid dyes from their individual solutions was studied at pH 4.8. It has been found that chemical immobilization of methyl red on silica surface causes increase of acid dyes sorption. The contribution of cooperative interactions, which arise between the aromatic groups of azo dyes immobilized in surface layer of silica and dye molecules in a solution, in the process of their sorption was confirmed. Modification of silica surface with capable to self-aggregation dyes is a promising way in chemical design of sorption-active materials.

FAMILY OF MORDOVIAN POPULATION OF THE REPUBLIC OF TATARSTAN: the Dynamics of Ethnic Development in the XX – the Beginning of the XXI Century

Introduction. The structure of the family, its livelihoods and in modern conditions retains its ethnic specificity, it still remains the cell of the reproduction of the ethnos, the carrier and successor of its cultural and everyday traditions. In this regard, family research is important for understanding modern national processes that occur in various regions of our country. Research methods. The comparative-historical method was used as the main one, which allowed revealing strata of various historical epochs in the life activity of the Mordovian family of the studied region, determining the stages of formation and further development of its structure-forming components. The method of processing statistical sources was also applied, which is now widely used in ethnology. Results. On the basis of the analyzed statistical material and scientific literature, the article traced the dynamics of quantitative changes that occurred in the family structure of the Mordovian population of the Republic of Tatarstan during the 20th and early 21st centuries, as well as the trends in the evolution of family rituals. This made it possible, on the one hand, to reveal the regional characteristics of these processes, and on the other, their commonality with similar phenomena among the Mordovian population of the neighboring regions. Discussion and conclusion. As a result of the study, it was revealed that at present the underlying factors of the ethnic development of the family of the Mordovian population of the Republic of Tatarstan were simplification of its demographic characteristics, as well as family rituals, the main functions of which were not sacral manifestations, but emotional, psychological and regulatory. These phenomena are basically similar to those occurring among other territorial groups of the Mordovian people.

Image-Symbols in the Tatar Poetry Between the 1920s-1930s

This article reveals the functional and semantic field of image-symbols in the Tatar poetry of the 1920s-1930s as exemplified by the poetic texts of Hadi Taqtaş, Musa Cəlil, Hasan Tufan and Ahmed Faizi. The structural and semantic field of the image-symbols formed in the literature between the 1920s and the 1930s significantly differs from the artistic and aesthetic search of the previous periods in the development of literature. Avant-garde experiments with the form of verses of the 1920s, complex literary devices and techniques, as well as the possibility of creating an image from a large number of mosaic details led poets to folklore image-symbols. At the same time, the authors observed the diversity of ideological images that often serve as symbols and structure-forming components in the structure of a poetic text. The research aims to study folklore and ideological image-symbols in the Tatar poetry of the 1920s-1930s and to reveal their structural-semantic and functional field in poetic texts. The scientific novelty of this article is determined by a different approach to the study of the system of images in poetic works, i.e. in the course of the study, the authors focus their attention on the symbolic use of images as structure-forming components. Within the framework of this research, the authors have proved that folklore and ideological symbols act as structure-forming components and are perceived as an opportunity to change artistic paradigms, restore ideological and philosophical depth, polysemy, the possibility of double interpretation and national traditions of the Tatar poetry. The fundamental method used in the course of this study is the hermeneutic approach that guides the reader’s receptive activity to the analysis of principles and techniques for creating images and image-symbols.

Technology Development and Determination of Vegetable Pastes Quality with Iodine-containing Raw Materials

The aim of the article is to develop the technology of new vegetable paste with iodinecontaining raw materials and to investigate their quality. Methodology of investigation consists in determining the optimum content of powders from hydrobionts in formulations of pastes, model compositions and research parties were developed. Sensory, functional and technological parameters of quality and chemical composition vegetable pastes investigation have been studied by conventional methods. During the research, standard physicochemical, organoleptic and rheological methods have been used. The main results of the article have been concluded in nutritional maintenance directions in the endemic territories of the normal function of the thyroid gland by using vegetable pastes with iodine-containing raw materials. It has been experimentally established that the use of powders from hydrobionts in the production of vegetable pastes will increase the of essential nutrients content and bring closer solutions of the deficiency problem of iodine and its synergists in human nutrition. Conclusions. The imported powders’ use of Norwegian production “Rieber Food Ingredients” makes it possible to produce vegetable pastes with iodine-containing raw materials with high organoleptic quality indicators without additional introduction of structure-forming components due to the presence in their composition of vegetable raw materials with high water-binding properties. New technologies in vegetable pastes with iodine-containing raw materials can be recommended for introduction in restaurant industry or industrial production establishments of food products and for the prevention of people suffering from thyroid diseases, disorders of the immune and cardiovascular systems and so on. The developed vegetable pastes with iodine-containing raw materials have a high cost price in comparison with traditional pastes. However, it should be noted that they have higher quality characteristics.

О семантических особенностях номинации в новозеландском тюремном жаргоне (на примере лексико-семантической группы «заключенный»)

The semantic features of the nomination in the New Zealand prison jargon are considered on the example of the lexical-semantic group “prisoner.” The relevance of the work is due to the increased interest in the study of social variants of the language in general, and their linguistic features, in particular. Semantic analysis of the studied units assumes their description in two planes - semasiological and onomasiological. Within the framework of semasiology, the organizational structure of the group is analyzed, its synonymic series and sub-standard lexemes in their relation to literary equivalents. In the context of onomasiology the ways of nomination of lexemes are investigated. The principles of two opposite directions for complex semantic description of nominative features of language units are revealed and systematized. The combination of two approaches makes it possible to reflect the organization of the lexical-semantic group under study in the most complete way, taking into account its structure-forming components, and to reveal the mechanisms of naming. It is found that the feature typical to this group is excessive variability, which is functionally determined and manifests itself in the presence of synonymous series. It is noted that the centres of attraction are the objects or phenomena most important for a particular social group. The presented scheme of the analysis of the lexico-semantic group “prisoner” is applicable in the description of other similar paradigmatic groups of the language substandard.

Влияние водопоглощения на свойства древесины в полимерцементном композиционном материале

The dependences of the main mechanical characteristics of polymer-matrix composite material on the content of the structure-forming components are examined: modifying fillers, retarder of crystallization reaction and reinforcing fillers, which are injected into the composition first separately, and then simultaneously. The studies revealed the presence of synergistic effects, ensuring the formation of a solid structure of finite composites, as well as hydrophobicity of the structure-forming components of the material.

Sewage Sludge Compost as Potting Media Component for ivy Pelargonium (Pelargonium peltatum (L.) L’Her.) Production

The increasing demand and raising cost of high quality peat for horticultural use have led to search for low cost substrates as an alternative. The source of materials for their production can be various types of industrial, municipal and agricultural waste. Most of them are rich in organic matter and minerals essential for plant growth. The aim of the study was to evaluate the growth and flowering of two ivy pelargonium cultivars (‘Beach’ and ‘Boneta’) grown in the media containing sphagnum peat and composts made from municipal sewage sludge and structure-forming components. Two different types of composts were used, consisting in equal proportions of sewage sludge and straw (SSRS) or leaves (SSL). The composts replaced 25% or 12.5% of sphagnum peat (v/v) in the growth media. A control media was sphagnum peat (100%) supplemented with a mixed fertilizer.It was found that the media containing both types of compost might be useful for growing ivy pelargonium. The most beneficial effect on the growth, foliage, and a decorative value of the pelargonium was observed for the medium containing 12.5% of SSL compost and 87.5% of peat. Decorative value of the pelargonium grown in the medium with 25% of SSL compost or with either dose of SSRS compost, did not differ from the control plants. The investigated cultivars differed in the number of shoot, color and area of leaves as well as length of stem of inflorescence. ‘Boneta’ cv. developed more stems and had greener leaves than those from ’Beach’ cultivar. While cultivar ‘Beach’ had greater area of leaves per plant and longer stem of inflorescence.

The professional world and professional activity of a medical university lecturer

Questions connected to the correlation of such notions as “image of the world” (A. N. Leontiev) and “invariant image of the world” (A. A. Leontiev) are considered. The proposition that professional activity is one of the bases for distinguishing invariant images of the world is substantiated. Based on the analysis of the professional activity of lecturers in medical institute clinical faculties, the notion “professional view of the world,” which reflects professional activity in an invariant image of the world, is introduced. The necessity for specifying the notion “professional view of the world” and introducing the notion “professional world,” describing professional measurement of the living space of medical institute lecturers, is also shown; the structure-forming components of this notion are singled out. It is also shown that the systems of relations by which the professional world is determined are by nature meaning relations (D. A. Leontiev).

Structure-forming components in crystals of ternary and quaternary 3d-metal complex fluorides.

Crystallochemical analysis and classification were performed for 139 ternary and quaternary complex fluorides with the general formula M1(n)M2(m)M3F(6), belonging to 33 structure types. Using coordination sequences and the uniformity criterion the structure-forming ionic sublattices or their combinations were found, which are responsible for the formation of stable periodic frameworks. Analysis of structure-forming motifs allows the interpretation of the crystal structures of complex fluorides as close packings of F ions with M1, M2 and M3 cations, partially occupying tetrahedral and octahedral voids, or as the packings of [M3F(6)] complex ions with M1 and M2 countercations in the voids. Cationic sublattices are noted to play an essential role, while forming crystal structures of complex fluorides. Relationships between the composition of structure-forming sublattices, the composition of compounds, and the size and charge of ions belonging to the sublattices were analysed under normal conditions, with thermal and high-pressure polymorphic transitions. Rules were formulated to predict the crystal structures of complex fluorides with a given chemical composition.

Search for structure-forming components in molecular crystals of binary compounds: a topological approach

Molecular crystal structures of 81 polymorphs of binary compounds are investigated with the method of coordination sequences and with the uniformity criterion for atomic sublattices. It is shown that using these tools one can estimate semi-quantitatively the relative force of intermolecular interactions and to find so-called structure-forming lattice, i.e. the atomic sublattice, where the most stable long-wavelength phonons are likely to spread. When a crystal consists of molecules with distinguished central atoms, the polarizability of surrounding atoms is found to dictate mainly the composition of the structure-forming lattice. If the polarizability is small, crystal structure is formed by molecules as a whole, otherwise surrounding atoms form the structure basis themselves, and it is their lattice that often is one of the close packings. It is shown that if the central atom of a molecule has stereoactive lone pair the central atom can form the structure-forming lattice together with surrounding atoms.