An influence of the type of rare-earth (RE) cation and composition of initial charge on the symmetry, structural features, and real composition of the single-crystal huntite family rare-earth scandium borates RESc3(BO3)4 (RE = Ce, Pr, Nd), grown by the Czochralski method, has been studied by single crystal and powder X-ray diffraction. A crystallization of scandium borates in the space groups C2/c (RE = Ce) and P321 (RE = Pr, Nd) has been found. Disordering in the structures with the space group P321, which has been first determined for the huntite family compounds, is due to the RE and Sc redistribution over two trigonal-prismatic sites to maintain the stability of crystal structure. The crystals grown from the initial charges NdSc3(BO3)4 and Nd1.25Sc2.75(BO3)4 are characterized by the greatest disordering, and they are isotypic, rather than isostructural, to the crystals obtained from the charges Pr1.1Sc2.9(BO3)4 and Pr1.25Sc2.75(BO3)4. A change in the unit cell parameters and interatomic distances depending on the RE radius and composition of the initial charge is found and explained. Analysis of our and literary data for RESc3(BO3)4 with the RE = La, Ce, Pr, Nd, Sm, Eu allowed to reveal a morphotropic series for scandium borates based on the size factor (the RE 3+ radius), suggest methods for evaluating the specific crystal symmetry depending on the type of RE cation, and propose factors affecting its realization. The comparison of huntite family REM 3(BO3)4 (M = Al, Ga, Sc) single crystals allowed to establish basic differences between their crystal structures, mainly due to the different sizes of RE and M ions.

The paper analyzes the possibilities of transforming C programming language constructs into objects of EO programming language. The key challenge of the method is the transpilation from a system programming language into a language of a higher level of abstraction, which doesn’t allow direct manipulations with computer memory. Almost all application and domain-oriented programming languages disable such direct access to memory. Operations that need to be supported in this case include the use of dereferenced pointers, the imposition of data of different types in the same memory area, and different interpretation of the same data which is located in the same memory address space. A decision was made to create additional EO-objects that directly simulate the interaction with computer memory as in C language. These objects encapsulate unreliable data operations which use pointers. An abstract memory object was proposed for simulating the capabilities of C language to provide interaction with computer memory. The memory object is essentially an array of bytes. It is possible to write into memory and read from memory at a given index. The number of bytes read or written depends on which object is being used. The transformation of various C language constructs into EO code is considered at the level of the compilation unit. To study the variants and analyze the results a transpiler was developed that provides necessary transformations. It is implemented on the basis of Clang, which forms an abstract syntax tree. This tree is processed using LibTooling and LibASTMatchers libraries. As a result of compiling a C program, code in EO language is generated. The considered approach turns out to be appropriate for solving different problems. One of such problems is static code analysis. Such solutions make it possible to isolate low-level code fragments into separate program objects, focusing on their study and possible transformations into more reliable code.