{
  "model": "J1J2",
  "lattice": "square",
  "n_sites": 256,
  "boundary": "P",
  "params": {
    "J2": 0.52
  },
  "instance_id": "J1J2/square_256_P_0.52",
  "rows": [
    {
      "energy": -503.808,
      "sigma": 0.1024,
      "energy_variance": null,
      "dof": 256,
      "einf": 0,
      "v_score": null,
      "method": "TPS",
      "method_detail": "extrapolated: χ → ∞ (contraction dimension Dc, quadratic in 1/Dc²)",
      "method_as_published": "TPS (D = 9) on the L x L torus, contraction dimension extrapolated",
      "family": "tensor network",
      "bound_type": "extrapolated",
      "bound_type_reason": "zero-variance or bond-dimension extrapolation; not an upper bound (assigned during source reading)",
      "reference": "Wang, Gu, Verstraete & Wen, Tensor-product state approach to spin-1/2 square J1-J2 antiferromagnetic Heisenberg model: Evidence for deconfined quantum criticality, Phys. Rev. B 94, 075143 (2016), arXiv:1112.3331",
      "peer_reviewed": true,
      "source": "sweep-allresults-2026-10-07",
      "provenance": "primary",
      "verified": {
        "checked_on": "2026-10-07",
        "method": "source text of arXiv:1112.3331 read locally (arXiv HTML or pypdf layout text); value copied from the harvested cell and the text, no LLM transcription of numbers; single reading",
        "reported_as": "-0.4920(1)",
        "note": "Table I, row J2 = 0.52, column L=16 | Energy per site in S.S units; the table's own L = 4 and L = 6 ED columns equal QMBL's exact rows. The finite-size values are extrapolated linearly in 1/Dc^2 (text), so they are not upper bounds.",
        "secondary_of": null
      },
      "compute": {
        "parameters": null,
        "gpu_hours": null,
        "device": null,
        "n_devices": null,
        "samples": null,
        "wall_clock": null,
        "cpu_core_hours": null,
        "bond_dimension": 9,
        "iterations": null,
        "reported_as": "method string: \"TPS (D = 9) on the L x L torus, contraction dimension extrapolated\"",
        "source": "the row's published method string (scripts/method_names.mjs, 2026-09-17)",
        "scope": "row",
        "confidence": "high",
        "note": "Only the numbers the method string states; nothing else about this run's cost is recorded."
      }
    }
  ],
  "url": "https://qmbl.org/i/J1J2/square_256_P_0.52/",
  "per_site_divisor": 1024,
  "per_site_label": "E/N (S.S)",
  "record": null,
  "no_record_reason": "no variational row"
}