Ordered PbHPO4 nanowires: Crystal structure, energy bands and optical properties from first principles

Structural, electronic and high-frequency dielectric properties of both the bulk crystal and the ordered nanostructured metamaterials, nanolayers (NLs) and nanowires (NWs) of hydrogen-bonded PbHPO4 are studied within the density functional theory. We have shown that all artificial structures considered by us may be equilibrated regarding the maximal forces acting on each atom up to the value not worse than 10(-6) eV/angstrom. The monoclinic symmetry not higher than the symmetry of the bulk PbHPO4 crystal, P2/c, is imposed both on each NL/NW proper and on their mutual space arrangement. Electronic band structure, density of states and partial densities of states, optical refractive indices and extinction coefficients have been calculated. We have displayed the evolution of electronic band properties going from the bulk single crystal to periodically ordered nanostructures, NLs and NWs. We have found significant anomalies in optical properties in visible and ultraviolet ranges of NWs studied in our research compared with those of bulk crystal. (C) 2017 Elsevier B.V. All rights reserved.