First-principles investigations of structural, mechanical, electronic and optical properties of U3Si2-type AlSc2Si2 under high pressure

The structural, elastic, electronic and optical properties for U3Si2-type AlSc2Si2 compound under pressure were systematically investigated by using the first-principles calculations. The values of elastic constants and elastic moduli indicate that AlSc2Si2 keeps mechanical stability under high pressure. The mechanical properties of AlSc2Si2 are compared with those of Al3Sc. The results indicate that AlSc2Si2 is harder than Al3Sc. Anisotropic constant AU and 3D curved surface of elastic moduli predict that AlSc2Si2 is obviously anisotropic under pressure. The electronic structure of AlSc2Si2 exhibits metallic character and the metallicity decreases with the elevated pressure. In addition, optical properties as a function of pressure were calculated and analyzed. The present work provides theoretical support for further experimental work and industrial applications.