{
  "model": "ShastrySutherland",
  "lattice": "square-tilted",
  "n_sites": 32,
  "boundary": "P",
  "params": {
    "J": 0.677248,
    "Jd": 1
  },
  "cluster": "32-site square cluster tilted by 45 degrees (periodic vectors (4,4) and (4,-4)), periodic boundaries; drawn in arXiv:cond-mat/0605464 Fig. 6 (second N = 32 cluster), distinct from its 4 x 8 stripe",
  "instance_id": "ShastrySutherland/square-tilted_32_P_J0.677248_Jd1",
  "rows": [
    {
      "energy": -48.0000021044,
      "sigma": null,
      "energy_variance": null,
      "dof": 32,
      "einf": 0,
      "v_score": null,
      "method": "ED",
      "ansatz": null,
      "method_detail": "Lanczos",
      "method_as_published": "exact diagonalisation (Lanczos)",
      "family": "other",
      "bound_type": "exact",
      "bound_type_reason": "numerically exact reference as stated by the source (assigned during source reading)",
      "reference": "Sindermann, Löw & Zittartz, Ground state properties of two spin models with exactly known ground states on the square lattice, Int. J. Mod. Phys. C 17, 1085 (2006), doi:10.1142/S0129183106009709, arXiv:cond-mat/0605464",
      "peer_reviewed": true,
      "source": "sweep-allresults-2026-10-20",
      "provenance": "primary",
      "verified": {
        "checked_on": "2026-10-20",
        "method": "source text of arXiv:cond-mat/0605464 read locally (arXiv HTML or pypdf layout text); value copied from the harvested cell and the text, no LLM transcription of numbers; first reading and an adversarial second reading (2026-10-20)",
        "reported_as": "-0.375000015810957",
        "note": "Table I (square N = 32), x = 0.677248; version read: arXiv text (sources/cond-mat-0605464.txt); the journal version was not reached from this session, to be read on the verification pass (RULES.md 8) | Eq. (1) H = J2 sum S.S (square bonds) + J1 sum S.S (diagonal dimer bonds), x = J2/J1, E0/N per site in units of J1 (the Fig. 1 caption swaps the labels; the tables fix them: E0/N = -0.375, the dimer-product energy, for all x below xc, and x = 0.8 equals the 6 x 6 ED of arXiv:2311.16889).",
        "secondary_of": null
      },
      "corrections": [
        {
          "field": "energy",
          "to": -48.0000021044,
          "reported_as": "-0.375000015810957 (E0/N, per site, units of J1 = Jd, S.S form)",
          "location": "Table I (square N = 32, left half), row J2/J1 = 0.677248 (arXiv:cond-mat/0605464)",
          "version_read": "recomputation (checks/exact-recompute-2026-10-families/); printed value read in arXiv:cond-mat/0605464v1 PDF, pypdf layout mode (shared cache sources/cond-mat-0605464v1.layout.txt), checked against the plain extraction, the project's sources/cond-mat-0605464.txt and a 110 dpi render of page 11; journal version (Int. J. Mod. Phys. C 17, 1085) not reached (HTTP 403)",
          "conversion": "recomputed -48.0000021044; stored -48.0000020238; difference -8.06e-08",
          "checked_on": "2026-10-24",
          "reason": "Ruled 2026-10-24 (rule for exact rows QMBL recomputed, 2026-09-30): QMBL's Lanczos (ed.c, S^z = 0 basis of the (4,4), (4,-4) torus, 601,080,390 states, dimer state deflated; 217 steps, the last 10 moved it by about 1e-10) gives -48.0000021044, below the dimer state at -48 and 8.06e-08 below the printed value (x 128), beyond its convergence. Lanczos Ritz values are upper bounds, so the source's run was not fully converged; the row carries QMBL's digits and the printed value stays here. Codes and outputs in checks/exact-recompute-2026-10-families/.",
          "source_entry": "famE-exact-recompute#9, famP2-10-1142-s0129183106009709#2 (qmbl-verify 2026-10-23); rule for recomputed exact rows, 2026-09-30, ruled for these rows 2026-10-24",
          "from": -48.0000020238
        },
        {
          "field": "sampled",
          "to": false,
          "reported_as": "-0.375000015810957",
          "location": "arXiv:cond-mat/0605464 Table I (square N = 32), x = 0.677248",
          "version_read": "the row's published method string (arXiv text, sources/cond-mat-0605464.txt)",
          "conversion": "none",
          "checked_on": "2026-10-25",
          "reason": "Deterministic: an exact (Lanczos) diagonalization carries no statistical error, but the label \"exact diagonalisation (Lanczos)\" matches none of isSampled's deterministic markers, so the row read as a sampled energy without an error bar; set as on the t-J Lanczos rows (ruled 2026-10-25).",
          "source_entry": "ruling of 2026-10-25 on the families port: sampled false on the cond-mat/0605464 exact rows",
          "from": true
        }
      ],
      "sampled": false
    }
  ],
  "url": "https://qmbl.org/i/ShastrySutherland/square-tilted_32_P_J0.677248_Jd1/",
  "per_site_divisor": 128,
  "per_site_label": "E/N (S.S)",
  "best": {
    "exact": {
      "energy": -48.0000021044,
      "sigma": null,
      "method": "ED",
      "ansatz": null,
      "method_detail": "Lanczos",
      "reference": "Sindermann, Löw & Zittartz, Ground state properties of two spin models with exactly known ground states on the square lattice, Int. J. Mod. Phys. C 17, 1085 (2006), doi:10.1142/S0129183106009709, arXiv:cond-mat/0605464",
      "bound_type": "exact",
      "energy_per_site": -0.375000016440625
    },
    "variational": null,
    "projected": null,
    "extrapolated": null,
    "approximate": null,
    "below_exact": []
  },
  "no_best_reason": null,
  "record": {
    "energy": -48.0000021044,
    "sigma": null,
    "method": "ED",
    "ansatz": null,
    "method_detail": "Lanczos",
    "reference": "Sindermann, Löw & Zittartz, Ground state properties of two spin models with exactly known ground states on the square lattice, Int. J. Mod. Phys. C 17, 1085 (2006), doi:10.1142/S0129183106009709, arXiv:cond-mat/0605464",
    "bound_type": "exact",
    "energy_per_site": -0.375000016440625
  },
  "no_record_reason": null
}