PROPERTIES OF HALF-HEUSLER DIAMOND-LIKE COMPOUNDS HAVING THE ZINCBLENDE STRUCTURE
>We investigated structural, electronic and elastic properties of 17 half-Heusler compounds A<sup>1</sup>B<sup>2</sup>X<sup>5</sup> with use ab-initio the program code CRYSTAL based on the density functional theory. A<sup>1</sup>B<sup>2</sup>X<sup>5</sup> crystals are analogous binary diamond-type compounds A<sup>3</sup>X<sup>5</sup> with the lattice zincblende (ZnS-type, space group F-43m). For all compounds, we have optimized the lattice constant. The calculated constant lattices and band gaps can be used as the basic information for selection of perspective materials for practical application. The calculated elastic constants show that the investigated materials are mechanically stable at ambient condition. Most of the materials are brittle. The calculated values of microhardness are comparable to those of binary analogues A<sup>3</sup>X<sup>5</sup> with the lattice zincblende (ZnS): AlN, AlP and AlAs.