Origin of the tetragonal-to-hexagonal phase transitions in Fe-doped BaTiO3: structures, inputs and total energies

Density-functional-theory dataset for Fe substitution in BaTiO3 and the competition between its tetragonal and hexagonal polymorphs, together with SrTiO3 and CaTiO3 control systems. The archive holds 700 structures. For every calculation it gives the unrelaxed input geometry and the converged relaxed geometry, together with the total energies and the configurational degeneracies needed to reproduce the reported averages, and the VASP input templates. 486 Fe-substituted BaTiO3 configurations, tetragonal and hexagonal, with and without one oxygen vacancy, at 1.85, 3.70 and 5.56 at.% Fe (all symmetry-inequivalent arrangements, each with its degeneracy) 95 Fe-substituted SrTiO3 and CaTiO3 controls 7 undoped host primitive cells 72 repeats at Ueff = 2 and 6 eV 4 configurations with the FeO6 shell held at a uniform bond length (Jahn-Teller reference) 8 electronic-structure runs: band unfolding, high-resolution density of states, frozen-ion SCF and the Fe-free reference cell 27 supercell-shape and relaxation-scheme tests 1 symmetry-disabled test The first three blocks are the 588 converged production relaxations the study is built on. Computational details are given in the paper, arXiv:2603.22571. The VASP input files used are included under inputs/. Pseudopotentials. VASP POTCAR files are licensed by the VASP Software GmbH and are not redistributed here. inputs/POTCAR_provenance.txt names the four PAW datasets (PAW_PBE Ba_sv 06Sep2000, Fe 06Sep2000, Ti_pv 07Sep2000, O_s 07Sep2000) and the species orderings that define the concatenation order for each structure. Start from README.md; manifest.csv indexes every deposited structure. Funding. Deutsche Forschungsgemeinschaft, Project-ID 463184206, SFB 1548. Computing time on the Lichtenberg high-performance computer at NHR4CES, TU Darmstadt (Project ID p0026451).