phonix-db/phonix-summary

---
pretty_name: Phonix Database

arxiv:
- arXiv:2504.21245

tags:
- materials
- phonon
- thermal-conductivity
- first-principles

license: cc-by-4.0
---

Summary of the Phonix database
==============================

The files on this page are a summary of
[the Phonix database](https://huggingface.co/datasets/phonix-hub/Phonix).

Column descriptions of `summary.csv`
--------------------------------------

| Column | Type | Description |
|--------|------|-------------|
| `mp_id` | string | Materials Project ID (e.g., `mp-7`). The same ID may appear in multiple rows for different calculations. |
| `input_dir` | string | Unique name. May differ from `mp_id` if the same material was computed with different parameters; duplicates are suffixed as `mp-{ID}-2`, `mp-{ID}-3`, etc. |
| `formula` | string | Reduced chemical formula |
| `spg_number` | int | International space group number |
| `natoms_prim` | float | Number of atoms in the primitive cell |
| `natoms_conv` | float | Number of atoms in the conventional cell |
| `natoms_sc` | float | Number of atoms in the supercell used for force constant calculations |
| `trans_conv2prim` | JSON (3×3) | Transformation matrix from the conventional cell to the primitive cell |
| `trans_conv2sc` | JSON (3×3) | Transformation matrix from the conventional cell to the supercell |
| `structure` | JSON | Crystal structure with keys: `cell` (3×3 lattice vectors in Å), `positions` (fractional coordinates), `symbols` (element symbols), `pbc` (periodic boundary conditions) |
| `volume[A^3]` | float | Volume of the primitive cell (ų) |
| `nac` | int | Non-analytical correction (NAC) method. `0`: NAC not applied; `1`: damping method proposed by Parlinski; `2`: mixed-space approach; `3`: Ewald method |
| `volume_relaxation` | int | Whether the volume was relaxed after two full relaxations and one site-relaxation calculation. `0`: not relaxed; `1`: volume relaxed |
| `scph` | int | Whether a self-consistent phonon (SCPH) calculation was performed. `0`: not performed; `1`: performed |
| `four` | int | Whether 4-phonon scattering was considered. `0`: not considered; `1`: considered |
| `kappa_type` | string | Thermal conductivity method. `3ph`: thermal conductivity calculated considering 3-phonon scattering. Other possible values: `3ph_lasso`, `scph`, `4ph`, `scph_4ph` |
| `qmesh` | string | q-point mesh used for the phonon Boltzmann transport equation (e.g., `14x14x14`) |
| `kp[W/mK]` | float | Particle-like (phonon gas model) contribution to lattice thermal conductivity, averaged over crystal axes (W/mK) |
| `kc[W/mK]` | float | Coherent (off-diagonal/wave-like) contribution to lattice thermal conductivity, averaged over crystal axes (W/mK) |
| `klat[W/mK]` | float | Total lattice thermal conductivity `klat = kp + kc`, averaged over crystal axes (W/mK) |
| `min_phfreq[cm^-1]` | float | Minimum phonon frequency in phonon dispersion and DOS (cm⁻¹). Negative values indicate imaginary modes (dynamical instability) |
| `max_phfreq[cm^-1]` | float | Maximum phonon frequency (cm⁻¹) |
| `fc2_error[%]` | float | Fitting error of the 2nd-order force constants (%) |
| `fc3_error[%]` | float | Fitting error of the 3rd-order force constants (%) |
| `calc_time[sec]` | float | Total wall-clock calculation time (seconds) |

### Note

- The transformation matrix is defined using the [Phonopy](https://phonopy.github.io/phonopy/setting-tags.html#primitive-axes-tag) convention.
- The anharmonic properties correspond to the values at 300 K.
- Please refer to the [official ALAMODE page](https://alamode.readthedocs.io/en/latest/faq.html) for details on the fitting error.