The aim of the proposed project is to advance our fundamental understanding of strength, stability and phase transformation in prospective intermetallic compounds by first-principles electronic structure calculations. The subject of our study will be the transition metal disilicides TSi2 (T = Mo, W, Nb, Ta, V, Cr, Ti) with the C11b, C40 and C54 structures, which are considered as a very promising basis for a new generation of high-temperature structural materials, and intermetallic compounds Ni3Al and Fe3Al with the L12 and D03 structures. For these compounds, we will simulate a tensile test and calculate theoretical tensile strength for various orientations of the loading axis. Further, we will study the displacive transformation paths connecting various crystal structures and determine their stability. The minima of total energy along transformation paths may correspond to atomic configurations found in extended defects (grain boundaries, antiphase boundaries, dislocation cores) - this correlation will also be analyzed.The calculated results will then provide a basis for construction of semi-empirical bond-order potentials, which will be used for computer simulation of extended defects.

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