Data

Files behind the figures, tables and numbers of the paper. The labels and descriptors are derived from the Alexandria phonon and electron-phonon release of 11 August 2025, which is published under CC BY 4.0 by Cavignac and coauthors.

h_alexandria.json (35 KB). Census of the scattering strength per proton over the Alexandria electron-phonon release: counts, distributions, largest values.
labels.csv (4,390 KB). One row per compound of the release with a spectral function: cell volume, hydrogen density, Hopfield sum, its hydrogen part, coupling constant, frequencies and the release's own transition temperatures.
descriptors.csv (1,836 KB). Descriptors of each cell used in the census and by the model.
summary.json (1 KB). Record counts of the release as read.
h_alexandria_points.json (119 KB). Hydrogen density and Hopfield parameter of the 4,619 labelled hydrides, as plotted.
h_census.json (177 KB). Scattering strength per proton from published tables and the megabar superhydrides.
hydrogen_density.json (38 KB). Hydrogen number density of known and proposed hydrides.
jellium.json (94 KB). A proton, and other nuclei, in an electron gas: phase shifts and scattering strength against density.
results.json (44 KB). Solutions of the Eliashberg equations for single-mode and two-mode spectra.
requirements.json (29 KB). Frequency and Hopfield parameter needed for a given transition temperature.
spectra.json (4 KB). Hopfield sums and transition temperatures recomputed from published spectra.
tails.json (15 KB). Tail of the calculated transition temperature near the convex hull.
tails_checks.json (3 KB). Checks of that tail: other thresholds, shapes and cuts.
frontier.json (3 KB). Ambient-pressure candidates: published range of calculated transition temperature, hull distance and outcome.
hexahydride_neighbours.json (5 KB). Known hydrides of the alkali platinum and alkali nickel systems in the Alexandria PBEsol database, with hull distance and gap.
records.json (2 KB). Record transition temperatures by year.
record_claims.json (3 KB). Record claims since 1986 that survived, failed or are open.
plane.json (3 KB). Published coupling constants and logarithmic frequencies.
paper-v4.md (177 KB). Draft 4 of the first paper, as text, in which the tests of the model were fixed before any training.
gao2025_fig2_wlog_lambda_tc.csv (226 KB). Marker coordinates read from a figure of Gao et al., Nat. Commun. 16, 8253 (2025), CC BY 4.0: frequency, coupling and transition temperature.
gao2025_fig4_tc_ehull.csv (142 KB). Marker coordinates read from a figure of the same paper: transition temperature against hull distance.

Deposited before the model was trained: manifest, splits, baseline predictions.