Fe3W (P4/mmm) - DFT relaxed

H5 anchor (mechanism decider, status=control, NOT a candidate): ordered Fe3W analog of the tier-1-clean Fe17W3 carrier (file 15265418-c679-4476-b784-caebd397df9b). a = 4.0804 A and interlayer 1.4568 A taken from Fe17W3; layers repeat Fe17W3's layer chemistry: mixed W/Fe checkerboard (W (0,0,0), Fe (0.5,0.5,0)) + pure Fe layer ((0,0.5,0.5),(0.5,0,0.5)). Validated 2026-09-06: P4/mmm #123 at symprec 0.01 and 0.1, 4 atoms, ordered, dmin 2.507 A, vol/atom 12.13 A3 (identical to Fe17W3), density 12.03 g/cm3. Pre-registered caveats: 25 vs 15 at% W; W-W 2.914 A along c where the carrier W has no W neighbor within 3.0 A.

Single source of truth for the rare-earth-free permanent magnet discovery program (quest 01a06c81). One row per (candidate, attempt). Schema follows skills/discovery-loop.md: property columns carry values only with action receipts in actionids; stage/status enums gate tier-2 spend; ciffileid is a file-asset reference. Excluded elements: La through Lu, Sc, Y. Row hypothesisid='schema-v1' is a schema probe, not a candidate.

H5 verdict: SUPPORTED. Ordered Fe3W anchor built from the Fe17W3 prototype has MAE 6.48 MJ/m3 (4.3x target); large-cell Fe17W3 MAE is worth commissioning.