Insights into electronic and optical properties of CrH hydrides

The first-principles calculations were employed to systematically explore the structural, electronic, and optical properties of cubic (C) and hexagonal (H1 and H2) CrH hydrides, for a deeper comprehension of physical characteristics. The optimized atomic coordinates and lattice parameters exhibit a good consistency with other theoretical results. Electronic properties such as band structure, densities of states, electron density difference, and Mulliken population indicate that the Cr-H bonds in these CrH hydrides exhibit strong covalent character. Predictions of the absorption coefficient a(?) and reflection coefficient R(?) suggest that longer wavelength lasers are ideal for synthesizing CrH coatings on substrate surfaces using NdYAG laser. The anisotropy of the optical properties of CrH hydrides were discussed using polycrystalline and oriented dielectric constants e(1)(0) and static refractive index n(0), and the anisotropy order is as H2> H1>C.