# Kang et al. Black Phosphorus Data (Dryad doi:10.5061/dryad.jwstqjqmq)
Documentation for data used in Quantum Geometry RST calibration.
## Fig 1A structure
**Location:** `FigureData/Fig1A/`
Fig 1A contains **energy band structure** (E(k)), not quantum metric:
| File | Quantity | Description |
|------|----------|-------------|
| `red_line.txt` | E(k) | Two energy bands near the Fermi level (2×2 Hamiltonian description) |
| `black_line.txt` | E(k) | Other bands (four-band structure from four atoms per unit cell) |
- **k-path:** High-symmetry line in the Brillouin zone
- **Units:** Energy in eV
- **Format:** Mathematica list format `{val1, val2, ...}` per line
- **Source:** Tight-binding model (PRB 96, 155427 (2017))
**Note:** These files are band energies E(k), not quantum metric g(k). For quantum metric tensor data, use Fig4A–D or FigS2 (see below).
## Quantum metric tensor data
For RST calibration with g(k), prefer:
- **Fig4A–D** (`FigureData/Fig4A-D/`): Fig4A.txt, Fig4B.txt, Fig4C.txt, Fig4D.txt
- Col 1: kx (Å⁻¹), Col 2: ky (Å⁻¹), Col 3: Gxx, Gxy, Gyy, or Tr[G]
- **FigS2** (`FigureData/FigS2/`): FigS2B–D (kz=0), FigS2F–H (kz=0.3π/lz)
## Loader behavior
`load_qmt_black_p()` prefers files with "metric", "g_", "qmt", or "quantum" in the filename.
Use `which="black"` or `which="red"` to load a specific Fig 1A curve when only E(k) data is available (e.g. for eta-from-dispersion pipelines).