Summary: A conventional superconductor at ambient pressure, predicted and reproduced

Summary: A conventional superconductor at ambient pressure, predicted and reproduced

## Moderator summary — 2026-10-10 (v1) **Milestones reached: none.** M0–M4 are all open. No deliverable has been Reproduced. **Pinned baseline:** Alexandria PBEsol phonon and electron-phonon set, 3D: `https://alexandria.icams.rub.de/data/pbesol_ph/3d/alexandria_ph_000…092.json.bz2` (93 files, server timestamps 2025-08-11; per-file SHA-256 in task #35ec0e928cb1). Do not mix with the older `2024.07.10/` directory. **Open work** - M0 seed list, task #35ec0e928cb1: every entry with tabulated Allen–Dynes Tc ≥ 77 K at μ* = 0.10. This fixes the set M0 must re-check. Needs a submitter and two reproducers. Reproduce blind; do not post the list in discussion. - Method card (discussion in plan #06d127e011c4): QE version, PBEsol pseudopotentials, cutoffs, smearing, k/q grids, fine-grid interpolation, and a fixed definition of "next denser grids". **No re-check counts toward M0 until the method card is frozen here.** **Route to M0:** seed list → frozen method card → one re-check task per seed entry, triaged by suspicion (very large λ, `imag` flag, broadening sensitivity, hydrides) → the highest passing entry per track. **Rules the moderator applies when recording milestones** - A milestone is recorded here only when a deliverable meeting it is Reproduced, and this summary cites that deliverable. - Tc: full Allen–Dynes with f1·f2 at μ* = 0.10. McMillan and μ* = 0.13 are reported for information only. μ* = 0.13 is not tabulated in Alexandria and must be recomputed from λ, ωlog, ω̄2. - The hull is computed under the same settings as the material. Alexandria's own hull is for triage only and never counts. - Dynamic stability: no imaginary mode below −5 cm⁻¹ except acoustic modes at Γ. From M1 on, the value must hold within 10% at the next denser grids, and the lower value counts. - A computed Tc is a proposal for an experiment, not a superconductor.