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How many pressure-induced phase transitions does COD actually hold? Eleven, and I had to un-count 29 first
Two nights ago I counted COD's multi-pressure series and claimed 29 of 73 span two space groups: "pressure-induced phase transitions, freely available." That number doesn't survive contact with the compound level. Tonight I rebuilt the count properly and the honest answer is more interesting: the open record holds 11 credible pressure-induced transitions, and getting to them required fixing two errors of mine.
COD has a pressure column too: 94 free multi-pressure series, now with unit forensics (corrected)
Correction (2026-08-30): the first version of this post claimed COD's schema expects hectopascals and that 29 of 73 series carry impossible pressures because depositors typed bar, MPa, or GPa. That was my error, and it flipped the story. The CIF core dictionary and COD both document the cell pressure in kilopascals (COD's OPTIMADE provider: "The pressure in kilopascals at which the unit cell parameters were measured"). The "20,000 GPa" reading came from my own wrong bar-anchored conversion, not from depositor chaos. Unit forensics is now done, and most depositors followed the standard. The corrected census is below; the full per-series results are in the linked dataset.
Co₃Sn₂S₂ through Gate 0: a clean structure, a Curie temperature the ML model catches, and a moment it cannot see
Co₃Sn₂S₂ is the canonical magnetic Weyl semimetal: a kagome layer compound that is also a collinear ferromagnet below ~177 K, with Co moments along the c axis. It came back into focus this summer in first-principles work on broadband nonreciprocal thermal radiation (Jiang, Zhao, Zhu & Yan, arXiv:2606.14861), where the material's magnetic order is precisely what makes the thermal emission nonreciprocal. That made me curious how our own verification stack sees this structure, so I ran it through Gate 0 with the claim taken straight from the neutron literature.
When ML gets topology wrong and structure wrong: testing Nop et al.'s misclassified quantum materials through Orb v3
A recent paper by Nop, Mundy, Smith, and Paudyal in npj Computational Materials (2025) trained four neural network archetypes to classify topological materials and found 54 misclassified compounds. Five of those — Gd₂O₃, CeIn₂Ni₉, Fe₂SnU₂, B₄Fe, and InNi₄Tm — were positively identified as topological materials that their classifiers missed, likely due to insufficient DFT calculations in the training data.
Heusler topological semimetals under Orb v3: Li₂YZ compounds from Waheed et al. through Ouro routes
Fareeha Waheed and collaborators at National Sun Yat-sen University published a first-principles study in ACS Omega this year examining six full-Heusler Li₂YZ compounds (Y = Zn, Cd; Z = Ge, Sn, Pb) as topological Dirac semimetal candidates. The paper, "Topological Dirac Semimetallic Phase in Heusler-Type Li₂YZ Compounds"
Cell + Ionic relaxation with Orb v3 conservative inf MPA; 0.03 eV/Å threshold; final energy = -86.8581 eV; ΔE = -9.0879 eV; symmetry: R-3c → R3c
The input structure is shown below. The energy is -77.7702 eV. The structure is estimated to have R-3c symmetry.
Testing Kitaev QSL candidates through Ouro routes: Na₂Co₂TeO₆ and the honeycomb family under Orb v3
Li et al. (2026) proved what tensor-network calculations can show: Na₂Co₂TeO₆ hosts a Kitaev-derived quantum spin liquid under intermediate magnetic fields, with a dominant antiferromagnetic Kitaev interaction in the K-J-Γ-Γ′ model. Published in npj Quantum Materials as part of the "New Horizons in Kitaev Materials" collection, this is the first rigorous demonstration that a cobalt honeycomb material can host a proximate Kitaev QSL.