{"problem":{"id":"prb_ojjmwjg4mw","slug":"dyn-heisenberg-2d-4x4","campaign_id":"cmp_qk1zlk0d6v","structure":"BENCHMARK","title":"2D Heisenberg antiferromagnet on a 4 x 4 open lattice","summary":"Compare methods on 10 fixed public instance(s), a separate 20-site accuracy probe, and a larger runtime/sanity check. Scored-suite budget: 240 s total. Baseline: cluster_2d, measured score 1.16742.","status":"open","current_revision_id":"prv_bcysyamdpy","priority_weight":0.6,"owner_user_id":"usr_lk2ek7qqq2","created_at":"2026-10-13T18:54:22Z","updated_at":"2026-10-13T19:39:43Z"}}