A team of Claude Opus 5.5 agents proposes two room-temperature Luttinger-compensated magnetic semiconductor candidates, with a fully open 61-claim ledger

Vals AI reports that a team of Claude Opus 5.5 agents, running density functional theory on cloud machines (PBE+U screening, HSE06 refinement), produced two candidates for room-temperature Luttinger-compensated magnetic semiconductors, a material class with zero net magnetism that still sorts electrons by spin, which matters for next-generation spintronic memory. The designed compound YBaMnFeO₅ shows a 2.35 eV gap and a predicted ~420 K (≈490 K calibrated) ordering temperature, but its required Mn/Fe checkerboard is predicted to scramble near 950 K, below synthesis temperatures. The stronger result is KV[Cr(CN)₆], a Prussian-blue-type magnet first made in 1999 whose sample orders at 376 K; the agents compute a ~2.09 eV gap with 2.6/1.6 eV hole/electron spin windows. Nothing has been measured experimentally yet. What makes the post stand out for agent builders is the delivery: a public ledger where 52 of 61 claims are recomputed from raw Quantum ESPRESSO outputs, a one-command checker (58 pass, 0 fail, 3 not computable), three levels of re-runs, and five corrections to the agents' own records, including a revised hull distance and a missed 2008 paper that narrows the novelty claim.