schema · 14 fields
A database of perovskite dft
Automate extraction for "A database of perovskite dft". Extract structured, evidence-grounded data points directly from hundreds of papers with source page coordinates.
Schema Field Definitions (14)
| Field Name | Data Type | Description |
|---|---|---|
| chemical_formula | string | The standardized chemical formula of the perovskite material modeled in the DFT calculation (e.g., CH3NH3PbI3, SrTiO3). Exclude non-perovskite phases. |
| crystal_system | string | The crystal system of the perovskite phase. Must be one of: cubic, tetragonal, orthorhombic, rhombohedral, hexagonal, monoclinic, triclinic. Return null when the paper does not provide enough information to select one. |
| space_group | string | The Hermann-Mauguin space group symbol or number specifying the crystal symmetry modeled in the DFT calculation (e.g., Pm-3m, I4/mcm). |
| dft_functional | string | The exchange-correlation approximation or functional used for the DFT calculation (e.g., PBE, HSE06, PBEsol, SCAN, B3LYP). |
| spin_orbit_coupling_included | boolean | Whether spin-orbit coupling (SOC) relativistic effects were explicitly included in the DFT calculation. |
| hubbard_u_applied | boolean | Whether an on-site Hubbard U correction (DFT+U) was applied to localized orbitals during the calculation. |
| magnetic_state | string | The magnetic configuration evaluated in the DFT calculation. Must be one of: nonmagnetic, ferromagnetic, antiferromagnetic, ferrimagnetic. Return null when the paper does not provide enough information to select one. |
| unit_cell_volume | number | Definition: The relaxed equilibrium unit cell volume calculated by DFT for the perovskite structure. Include: Explicitly reported numerical values for the DFT-relaxed equilibrium unit cell volume. Exclude: Unit cell volumes calculated or derived from reported lattice parameters; experimental or unrelaxed volumes where lattice parameters were held fixed during coordinate relaxation. Context/group/timepoint: Ground-state DFT structural optimization of the perovskite phase. Representation and unit: Numerical value only. Return null when: The relaxed equilibrium unit cell volume is not explicitly stated in the paper text, tables, or supplementary information, or when lattice parameters were held fixed at experimental values. |
| unit_cell_volume_unit | string | The unit associated with the extracted unit_cell_volume, exactly as reported in the paper (e.g., ų, nm³). |
| band_gap_type | string | The electronic nature of the calculated band gap. Must be one of: direct, indirect. Return null when the paper does not provide enough information to select one. |
| calculated_band_gap | number | The numerical magnitude of the electronic band gap computed using the specified DFT functional. Exclude experimental or cited literature reference values. |
| calculated_band_gap_unit | string | The unit associated with the calculated_band_gap value, exactly as reported in the paper (e.g., eV). |
| formation_energy | number | The thermodynamic formation energy or energy above the convex hull computed for the perovskite structure via DFT. Exclude cited literature values. |
| formation_energy_unit | string | Definition: The unit associated with the formation_energy value, exactly as reported in the paper. Include: The unit explicitly reported for the calculated thermodynamic formation energy (e.g., eV/atom, eV/formula unit, meV/atom). Exclude: Units associated with other energetic properties such as band gaps, deformation energies, or total energies. Context/group/timepoint: Coupled directly to the extracted DFT formation_energy. Representation and unit: String representing the unit exactly as reported. Return null when: formation_energy is missing, not reported, or not calculated via DFT. |
Data Verification Status Taxonomy
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Extracted
Value located and extracted from the full-text PDF by the Kateeb engine.
Model-Agreed
An independent second model produced a compatible value during automated second-pass review.
Human-Reviewed
A named researcher audited the value against the visual page coordinates.
Benchmark-Validated
Performance evaluated against a standardized, published evaluation protocol.
Replicated
An independent external research group reproduced the extraction and experimental result.