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HfTi_BCC_SolidSolution_128atoms_VASP6

We performed density functional theory (DFT) calculations for body-centered-cubic (BCC) structures with 128 lattices sites of solid solution binary alloys hafnium-titanium (Hf-Ti). The electronic structures of alloys have been calculated using Vienna Ab initio Simulation Package (VASP). Within this package the DFT approach is used to reduce many-body Schrodinger equation to set of single particle Kohn-Sham (KS) equations. The generalized electronic exchange-correlation functional is described by generalized gradient approximation with the Perdew-Burke-Ernzerhof parametrization. The electron-ion interactions is described by pseudopotentials developed within the plane-wave basis projector augmented-wave (PAW) approach. These pseudopotentials are available at the VASP portal (http://cms.mpi.univie.ac.at/vasp/). Our calculations have been run with the pseudopotentials treating s and p semi-core states as valence in case for the elements Hf and Ti. The electronic densities and potentials are expanded over plane-waves with energy cutoff of 350 eV. 2x2x2 k-mesh and normal precision were used. The alloys were modeled by supercell containing 128 randomly distributed atoms. At initial step the atoms occupy perfect bcc lattice cites. This initial structure was optimized until energy changes less than 1e-6 eV, while forces acting on atoms don't exceed 1e-2 eV/angstrom. The electron-ion interaction is described by PAW pseudopotentials. The calculations have been collected by sampling chemical compositions across the entire compositional range. The chemical compositions have been sampled by progressively changing the number of atoms per constituent by 4. For each chemical composition of binaries and ternaries, the first-principle calculations have been run for 100 randomized arrangements of the constituents on the BCC lattice sites. We collected data for a total of 3,100 randomized atomic structures over 31 chemical compositions. The calculations have been collected on Air Force HPC11 cluster using the VASP 6.5.1. Additional methodology and file structure information is available in the dataset README.txt file.

36 MATERIALS SCIENCE↗

Materials Data on HfTi by Materials Project

HfTi crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Hf is bonded to six equivalent Hf and six equivalent Ti atoms to form distorted HfHf6Ti6 cuboctahedra that share corners with eighteen equivalent HfHf6Ti6 cuboctahedra, edges with six equivalent HfHf6Ti6 cuboctahedra, edges with twelve equivalent TiHf6Ti6 cuboctahedra, faces with eight equivalent HfHf6Ti6 cuboctahedra, and faces with twelve equivalent TiHf6Ti6 cuboctahedra. All Hf–Hf bond lengths are 3.09 Å. All Hf–Ti bond lengths are 3.01 Å. Ti is bonded to six equivalent Hf and six equivalent Ti atoms to form distorted TiHf6Ti6 cuboctahedra that share corners with eighteen equivalent TiHf6Ti6 cuboctahedra, edges with six equivalent TiHf6Ti6 cuboctahedra, edges with twelve equivalent HfHf6Ti6 cuboctahedra, faces with eight equivalent TiHf6Ti6 cuboctahedra, and faces with twelve equivalent HfHf6Ti6 cuboctahedra. All Ti–Ti bond lengths are 3.09 Å.

36 MATERIALS SCIENCE↗

Materials Data on HfTi(PbO3)2 by Materials Project

HfTi(PbO3)2 is Pb(Zr_(1-x)Ti_x)O3-derived structured and crystallizes in the tetragonal I4mm space group. The structure is three-dimensional. Hf4+ is bonded to six O2- atoms to form distorted HfO6 octahedra that share corners with six equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 0–17°. There are a spread of Hf–O bond distances ranging from 1.95–2.38 Å. Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with six equivalent HfO6 octahedra. The corner-sharing octahedra tilt angles range from 0–17°. There are a spread of Ti–O bond distances ranging from 1.84–2.26 Å. Pb2+ is bonded in a 12-coordinate geometry to eight O2- atoms. There are a spread of Pb–O bond distances ranging from 2.57–2.90 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Hf4+, one Ti4+, and two equivalent Pb2+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Hf4+, one Ti4+, and four equivalent Pb2+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to one Hf4+, one Ti4+, and four equivalent Pb2+ atoms.

36 MATERIALS SCIENCE↗