First-Principles Investigations on Structural, Elastic, Electronic, and Optical Properties of Tetragonal HfSiO4

Structural parameters, elastic, mechanical, electronic, chemical bonding, and optical properties of tetragonal HfSiO₄ have been investigated using the plane-wave ultrasoft pseudopotential technique based on the first-principles density-functional theory. The ground-state properties obtained by minimizing the total energy are in agreement with the available experimental and theoretical data. This compound is found to be mechanically stable, and we have obtained the bulk, shear, and Young's modulus; Poisson's coefficient; and Lamé's constants. We have estimated the Debye temperature of tetragonal HfSiO₄ from the acoustic velocity. Electronic and chemical bonding properties have been studied. Moreover, the complex dielectric function, refractive index, extinction coefficient, absorption coefficient, energy-loss spectrum, optical reflectivity, and complex conductivity function are calculated and analyzed.