{
  "model": "Hchain",
  "lattice": "chain",
  "n_sites": 50,
  "boundary": "O",
  "params": {
    "N_up": 25,
    "N_dn": 25,
    "R": 1.4,
    "basis": "cc-pVTZ"
  },
  "instance_id": "Hchain/chain_50_O_R1.4_ccpvtz",
  "rows": [
    {
      "energy": -27.0317,
      "sigma": 0.0016,
      "energy_variance": null,
      "dof": 50,
      "einf": null,
      "v_score": null,
      "method": "ph-AFQMC",
      "ansatz": null,
      "method_detail": "",
      "method_as_published": "AFQMC [phaseless]",
      "family": "AFQMC / GFMC",
      "bound_type": "projected",
      "bound_type_reason": "AFQMC, fixed-node or lattice-regularised DMC, coupled cluster, MRCI+Q or an embedding method; not a bound (RULES.md 13.4; assigned during source reading)",
      "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
      "peer_reviewed": true,
      "source": "track3-2026-10-20",
      "provenance": "primary",
      "verified": {
        "checked_on": "2026-10-20",
        "method": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0; source text of arXiv:1705.01608 read locally (pypdf layout text; the generator finds every value again on its line), no LLM transcription of numbers; single reading",
        "reported_as": "-27.0317 0.0016 (total for N = 50; second number the stated uncertainty)",
        "note": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/AFQMC_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference | Hartree, lengths in bohr (Appendix B). Total energies with nuclear repulsion: FCI/STO-6G H10 at R = 1.8 is -5.42438538 in the dataset and -0.542439 per atom in Table II, and the paper's FCI E_inf = -0.471039 is the STO-6G hydrogen-atom energy per atom.",
        "secondary_of": null,
        "second_read": {
          "checked_on": "2026-10-24",
          "scope": "value",
          "method": "arXiv:1705.01608v2 (6 Nov 2017, sources/1705.01608.txt and .pdf) and journal PRX 7, 031059 (sources/1705.01608-PhysRevX.7.031059.txt); dataset github.com/simonsfoundation/hydrogen-benchmark-PRX at b99a183, raw files re-fetched from raw.githubusercontent.com (all HTTP 200) and compared with the committed TSV; node scripts compare.mjs, gap.mjs, others.mjs in this folder",
          "location": "dataset file N_50_OBC/R_1.4/AFQMC_basis-TZ",
          "reported_as": "-27.0317 0.0016",
          "conversion": "-27.0317 Eh total (file stores the total, nuclear repulsion included); per atom -27.0317 / 50 = -0.54063400; sigma 0.0016 total = 0.0000320000 per atom",
          "note": "mechanical match: raw GitHub file = committed TSV = reported_as; eps*N and sigma*N reproduce the file to 1e-9; N_up = N_dn = N/2, OBC chain, basis token matches the file's basis key; method AFQMC phaseless, projected, sampled (RULES §13.4); no DMRG or FCI on this instance to test against; number printed only in the dataset; the paper's tables print H10 and TDL values only (searched both texts for the total and the 5-decimal per-atom value: only coincidental TDL-table matches); no duplicate row on the instance (no other AFQMC row in the sweep file; track 3 has no data/Hchain files)",
          "secondary_of": null,
          "source_entry": "h-motta17-afqmc-c2#34 (qmbl-verify 2026-10-23/24, verified)"
        }
      }
    },
    {
      "energy": -26.908113,
      "sigma": null,
      "energy_variance": null,
      "dof": 50,
      "einf": null,
      "v_score": null,
      "method": "DMET",
      "ansatz": null,
      "method_detail": "fragment of 2 atoms",
      "method_as_published": "DMET [fragment of 2 atoms]",
      "family": "other",
      "bound_type": "projected",
      "bound_type_reason": "AFQMC, fixed-node or lattice-regularised DMC, coupled cluster, MRCI+Q or an embedding method; not a bound (RULES.md 13.4; assigned during source reading)",
      "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
      "peer_reviewed": true,
      "source": "track3-2026-10-20",
      "provenance": "primary",
      "verified": {
        "checked_on": "2026-10-20",
        "method": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0; source text of arXiv:1705.01608 read locally (pypdf layout text; the generator finds every value again on its line), no LLM transcription of numbers; single reading",
        "reported_as": "-26.908113 (total for N = 50)",
        "note": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/DMET_2_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference | Hartree, lengths in bohr (Appendix B). Total energies with nuclear repulsion: FCI/STO-6G H10 at R = 1.8 is -5.42438538 in the dataset and -0.542439 per atom in Table II, and the paper's FCI E_inf = -0.471039 is the STO-6G hydrogen-atom energy per atom.",
        "secondary_of": null,
        "second_read": {
          "checked_on": "2026-10-24",
          "scope": "value",
          "method": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX at b99a183a5a2dd2a471bbde3f3c4952cc3d2432ea (commit 2017-10-09 by the first author), fetched fresh from raw.githubusercontent.com on 2026-10-24 and compared with sources/1705.01608-data-b99a183.tsv; method text: PRX 7, 031059 journal text (sources/1705.01608-PhysRevX.7.031059.txt) and arXiv:1705.01608v2 text, Appendix A 3 a",
          "location": "file N_50_OBC/R_1.4/DMET_2_basis-TZ (single number, total energy in Hartree with nuclear repulsion)",
          "reported_as": "-26.908113 (total, Hartree, N = 50)",
          "conversion": "-26.908113 / 50 = -0.5381622600 Ha per atom; stored eps x N = -26.908113 (difference 0.0e+0)",
          "note": "N = 50, open chain, R = 1.4 bohr, cc-pVTZ, N_up = N_dn = 25, DMET[2] with FCI solver; bound_type projected (RULES 13.4); no sigma (deterministic). Number first printed in the dataset; not printed in the journal or arXiv v2 tables (text search of both). No other row with this value on the instance; data/Hchain does not exist (track 3 held), so no cross-batch duplicate.",
          "secondary_of": null,
          "source_entry": "h-motta17-dmet-c2#35 (qmbl-verify 2026-10-23/24, verified)"
        }
      },
      "sampled": false,
      "corrections": [
        {
          "field": "sampled",
          "to": false,
          "reported_as": "-26.908113 (total for N = 50)",
          "location": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/DMET_2_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference",
          "checked_on": "2026-10-20",
          "reason": "Deterministic, not a Monte Carlo estimate, as the track-3 reader recorded it (pass row `sampled`); the method string alone reads the other way (units.mjs, isSampled).",
          "source_entry": "passes/track3/sweep-rows-2026-10-20-hydrogen.json"
        }
      ]
    },
    {
      "energy": -27.01495,
      "sigma": null,
      "energy_variance": null,
      "dof": 50,
      "einf": null,
      "v_score": null,
      "method": "RCCSD(T)",
      "ansatz": null,
      "method_detail": "",
      "method_as_published": "RCCSD(T)",
      "family": "FCIQMC / CC",
      "bound_type": "approximate",
      "bound_type_reason": "finite-order perturbation theory, GW, or a perturbative correction to coupled cluster (track 3, 2026-10-21); error of unknown sign (RULES.md 13.4; assigned during source reading)",
      "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
      "peer_reviewed": true,
      "source": "track3-2026-10-20",
      "provenance": "primary",
      "verified": {
        "checked_on": "2026-10-20",
        "method": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0; source text of arXiv:1705.01608 read locally (pypdf layout text; the generator finds every value again on its line), no LLM transcription of numbers; single reading",
        "reported_as": "-27.01495 (total for N = 50)",
        "note": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/RCCSD(T)_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference | Hartree, lengths in bohr (Appendix B). Total energies with nuclear repulsion: FCI/STO-6G H10 at R = 1.8 is -5.42438538 in the dataset and -0.542439 per atom in Table II, and the paper's FCI E_inf = -0.471039 is the STO-6G hydrogen-atom energy per atom.",
        "secondary_of": null,
        "second_read": {
          "checked_on": "2026-10-24",
          "scope": "value",
          "method": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX at b99a183a5a2dd2a471bbde3f3c4952cc3d2432ea (2017-10-09, authors' upload, CC BY 4.0): raw file fetched fresh from raw.githubusercontent.com on 2026-10-24 (sources/1705.01608-data-raw-rccsd-t.json, out/h-motta17-rccsd-t--c1/fetch_raw.mjs) and compared byte-for-byte with the committed TSV qmbl-wt-hydrogen/sources/1705.01608-data-b99a183.tsv (compare.py); conventions from journal Phys. Rev. X 7, 031059 (2017; published 2017-09-28, corrected 2021-03-24), publisher PDF text qmbl-wt-hydrogen/sources/1705.01608-PhysRevX.7.031059.txt; arXiv:1705.01608v2 (dated 2017-11-08, PDF stamp 'arXiv:1705.01608v2'), sources/1705.01608.txt; table cells parsed with python (out/h-motta17-rccsd-t--c1/compare.py)",
          "location": "dataset file N_50_OBC/R_1.4/RCCSD(T)_basis-TZ (the paper prints no finite-basis RCCSD(T) value for this N and basis: Table II is STO-6G H10, Table III CBS H10, Table IV MRCI+Q only, Tables V-VI thermodynamic limit)",
          "reported_as": "-27.01495 (Hartree, total for N = 50, nuclear repulsion included)",
          "conversion": "total as printed; per atom -27.01495 / 50 = -0.540299000 = stored eps -0.540299",
          "note": "RCCSD(T) on an RHF reference (Sec. III, journal lines 226-229; App. A 1, PySCF, journal lines 806-820); open equispaced chain, R in bohr, neutral, N_up = N_dn = N/2 (lowest-energy RHF determinant); bound_type approximate per RULES §13.4 (CCSD(T), provisional 2026-10-21); no sigma for a finite-basis deterministic energy",
          "secondary_of": null,
          "source_entry": "h-motta17-rccsd-t--c1#87 (qmbl-verify 2026-10-23/24, verified)"
        }
      },
      "sampled": false,
      "corrections": [
        {
          "field": "sampled",
          "to": false,
          "reported_as": "-27.01495 (total for N = 50)",
          "location": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/RCCSD(T)_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference",
          "checked_on": "2026-10-20",
          "reason": "Deterministic, not a Monte Carlo estimate, as the track-3 reader recorded it (pass row `sampled`); the method string alone reads the other way (units.mjs, isSampled).",
          "source_entry": "passes/track3/sweep-rows-2026-10-20-hydrogen.json"
        }
      ]
    },
    {
      "energy": -26.96829,
      "sigma": null,
      "energy_variance": null,
      "dof": 50,
      "einf": null,
      "v_score": null,
      "method": "RCCSD",
      "ansatz": null,
      "method_detail": "",
      "method_as_published": "RCCSD",
      "family": "FCIQMC / CC",
      "bound_type": "projected",
      "bound_type_reason": "AFQMC, fixed-node or lattice-regularised DMC, coupled cluster, MRCI+Q or an embedding method; not a bound (RULES.md 13.4; assigned during source reading)",
      "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
      "peer_reviewed": true,
      "source": "track3-2026-10-20",
      "provenance": "primary",
      "verified": {
        "checked_on": "2026-10-20",
        "method": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0; source text of arXiv:1705.01608 read locally (pypdf layout text; the generator finds every value again on its line), no LLM transcription of numbers; single reading",
        "reported_as": "-26.96829 (total for N = 50)",
        "note": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/RCCSD_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference | Hartree, lengths in bohr (Appendix B). Total energies with nuclear repulsion: FCI/STO-6G H10 at R = 1.8 is -5.42438538 in the dataset and -0.542439 per atom in Table II, and the paper's FCI E_inf = -0.471039 is the STO-6G hydrogen-atom energy per atom.",
        "secondary_of": null,
        "second_read": {
          "checked_on": "2026-10-24",
          "scope": "value",
          "method": "journal PRX 7, 031059 (2017) publisher PDF, pypdf layout extraction (raw/journal-layout.txt), cross-read with the project text sources/1705.01608-PhysRevX.7.031059.txt; arXiv:1705.01608v2 PDF (dated November 8, 2017), pypdf layout (raw/arxiv-layout.txt) and sources/1705.01608.txt; data repository github.com/simonsfoundation/hydrogen-benchmark-PRX at b99a183, files fetched raw from GitHub 2026-10-24 (raw/rccsd-files-b99a183.json) and compared with sources/1705.01608-data-b99a183.tsv by check.mjs",
          "location": "dataset file N_50_OBC/R_1.4/RCCSD_basis-TZ (github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183, 2017-10-09, uploaded by the authors); raw GitHub content '-26.96829<nbsp>' equals the committed TSV line",
          "reported_as": "-26.96829 (file content, total for N = 50, Hartree)",
          "conversion": "stored eps -0.5393658 x 50 = -26.96829 = file value; -26.96829 / 50 = -0.53936580 per atom",
          "note": "Instance agrees: equally spaced H50 chain, open (finite molecule), R = 1.4 bohr, dataset basis label TZ = cc-pVTZ (README basis list), N_up = N_dn = 25. Number first printed in the dataset, cited to it with the paper as method reference (RULES 8); the paper prints no finite-basis RCCSD table for N = 50. bound_type projected (RULES 13.4), sampled false, sigma null (file holds one number) agree. Same-instance dataset values: AFQMC -27.0317; the row is above every DMRG/AFQMC/MRCI+Q value on the instance. Computed with near-linear-dependent basis vectors removed at overlap threshold 1e-7 (App. A a: affects cc-pVTZ/QZ at R < 1.6 and cc-pVDZ at R < 1.4; the authors give ~1e-6 Ha per atom as the size of threshold effects): noted, not a different instance. Duplicate scan: no data/Hchain file exists (track 3 held); no row from another batch on this instance carries this number.",
          "secondary_of": null,
          "source_entry": "h-motta17-rccsd-c1#85 (qmbl-verify 2026-10-23/24, verified)"
        }
      },
      "sampled": false,
      "corrections": [
        {
          "field": "sampled",
          "to": false,
          "reported_as": "-26.96829 (total for N = 50)",
          "location": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/RCCSD_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference",
          "checked_on": "2026-10-20",
          "reason": "Deterministic, not a Monte Carlo estimate, as the track-3 reader recorded it (pass row `sampled`); the method string alone reads the other way (units.mjs, isSampled).",
          "source_entry": "passes/track3/sweep-rows-2026-10-20-hydrogen.json"
        }
      ]
    },
    {
      "energy": -25.6687432,
      "sigma": null,
      "energy_variance": null,
      "dof": 50,
      "einf": null,
      "v_score": null,
      "method": "HF",
      "ansatz": null,
      "method_detail": "restricted, basis vectors with overlap eigenvalue below 1e-7 removed (near linear dependence; Appendix A.1)",
      "method_as_published": "RHF [basis vectors with overlap eigenvalue below 1e-7 removed (near linear dependence; Appendix A.1)]",
      "family": "mean field",
      "bound_type": "variational",
      "bound_type_reason": "the energy of a stated wave function (Hartree-Fock, DMRG at a stated bond dimension, MRCI, VMC, a neural-network state); an upper bound in the instance's basis (RULES.md 13.4; assigned during source reading)",
      "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
      "peer_reviewed": true,
      "source": "track3-2026-10-20",
      "provenance": "primary",
      "verified": {
        "checked_on": "2026-10-20",
        "method": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0; source text of arXiv:1705.01608 read locally (pypdf layout text; the generator finds every value again on its line), no LLM transcription of numbers; single reading",
        "reported_as": "-25.6687432 (total for N = 50)",
        "note": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/RHF_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference | Hartree, lengths in bohr (Appendix B). Total energies with nuclear repulsion: FCI/STO-6G H10 at R = 1.8 is -5.42438538 in the dataset and -0.542439 per atom in Table II, and the paper's FCI E_inf = -0.471039 is the STO-6G hydrogen-atom energy per atom.",
        "secondary_of": null
      },
      "sampled": false,
      "corrections": [
        {
          "field": "method_detail",
          "from": "",
          "to": "basis vectors with overlap eigenvalue below 1e-7 removed (near linear dependence; Appendix A.1)",
          "checked_on": "2026-10-24",
          "reported_as": "For the largest basis sets cc-pVTZ, cc-pVQZ, and cc-pV5Z at geometries R < 1.6 aB and cc-pVDZ at R < 1.4 aB, the Gaussian basis is nearly linearly dependent. We remove linearly dependent vectors with an overlap threshold of 10^-7. Although a smaller threshold could be used in the Hartree-Fock calculation, changing the energy by ~10^-6 EHa per atom, we find the resulting CCSD calculations with smaller thresholds to be numerically unstable.",
          "location": "PRX 7, 031059, Appendix A.1 (coupled cluster), p. 031059-13; same text arXiv v2 line 790-800 of sources/1705.01608.txt; main text Sec. V A: 'To deal with basis-set linear dependence, which becomes relevant at the shortest bond lengths and largest basis sets, we apply a threshold to eigenvalues of the overlap matrix.'",
          "version_read": "journal text (sources/1705.01608-PhysRevX.7.031059.txt) and arXiv:1705.01608v2; identical",
          "conversion": "none",
          "reason": "R = 1.4 bohr, cc-pVTZ: inside the paper's stated linear-dependence window, so the energy is for the cc-pVxZ space with near-null vectors removed (paper: about 1e-6 Eh per atom effect on HF). The row should say so; value unchanged. The paper states the threshold in the CC subsection, whose RHF references the dataset RHF files most plausibly are.",
          "source_entry": "h-motta17-rhf-c2#35 (qmbl-verify 2026-10-23/24, correction; skeptic upheld)"
        },
        {
          "field": "sampled",
          "to": false,
          "reported_as": "-25.6687432 (total for N = 50)",
          "location": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/RHF_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference",
          "checked_on": "2026-10-20",
          "reason": "Deterministic, not a Monte Carlo estimate, as the track-3 reader recorded it (pass row `sampled`); the method string alone reads the other way (units.mjs, isSampled).",
          "source_entry": "passes/track3/sweep-rows-2026-10-20-hydrogen.json"
        }
      ]
    },
    {
      "energy": -25.694342,
      "sigma": null,
      "energy_variance": null,
      "dof": 50,
      "einf": null,
      "v_score": null,
      "method": "HF",
      "ansatz": null,
      "method_detail": "unrestricted, basis vectors with overlap eigenvalue below 1e-7 removed (near linear dependence; Appendix A.1)",
      "method_as_published": "UHF [basis vectors with overlap eigenvalue below 1e-7 removed (near linear dependence; Appendix A.1)]",
      "family": "mean field",
      "bound_type": "variational",
      "bound_type_reason": "the energy of a stated wave function (Hartree-Fock, DMRG at a stated bond dimension, MRCI, VMC, a neural-network state); an upper bound in the instance's basis (RULES.md 13.4; assigned during source reading)",
      "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
      "peer_reviewed": true,
      "source": "track3-2026-10-20",
      "provenance": "primary",
      "verified": {
        "checked_on": "2026-10-20",
        "method": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0; source text of arXiv:1705.01608 read locally (pypdf layout text; the generator finds every value again on its line), no LLM transcription of numbers; single reading",
        "reported_as": "-25.694342 (total for N = 50)",
        "note": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/UHF_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference | Hartree, lengths in bohr (Appendix B). Total energies with nuclear repulsion: FCI/STO-6G H10 at R = 1.8 is -5.42438538 in the dataset and -0.542439 per atom in Table II, and the paper's FCI E_inf = -0.471039 is the STO-6G hydrogen-atom energy per atom.",
        "secondary_of": null
      },
      "sampled": false,
      "corrections": [
        {
          "field": "method_detail",
          "from": "",
          "to": "basis vectors with overlap eigenvalue below 1e-7 removed (near linear dependence; Appendix A.1)",
          "checked_on": "2026-10-24",
          "reported_as": "For the largest basis sets cc-pVTZ, cc-pVQZ, and cc-pV5Z at geometries R < 1.6 aB and cc-pVDZ at R < 1.4 aB, the Gaussian basis is nearly linearly dependent. We remove linearly dependent vectors with an overlap threshold of 10^-7. Although a smaller threshold could be used in the Hartree-Fock calculation, changing the energy by ~10^-6 EHa per atom, we find the resulting CCSD calculations with smaller thresholds to be numerically unstable.",
          "location": "PRX 7, 031059, Appendix A 1 a (coupled cluster), p. 031059-13 (journal text lines 767-778); arXiv v2 text lines 790-800 (same sentences, past tense); main text Sec. IV C: 'To deal with basis-set linear dependence, which becomes relevant at the shortest bond lengths and largest basis sets, we apply a threshold to eigenvalues of the overlap matrix.'",
          "version_read": "journal text (sources/1705.01608-PhysRevX.7.031059.txt) and arXiv:1705.01608v2 (sources/1705.01608.txt); same statement",
          "conversion": "none",
          "reason": "R = 1.4 bohr, cc-pVTZ: inside the paper's stated linear-dependence window, so the UHF energy is for the cc-pVxZ space with near-null overlap vectors removed (paper: about 1e-6 Eh per atom effect on Hartree-Fock). The row should say so; value unchanged (located: dataset file N_50_OBC/R_1.4/UHF_basis-TZ = -25.694342, identical to reported_as). The threshold is stated in the CC subsection, whose UHF references (UCCSD) the dataset UHF files most plausibly are. Same proposal as group h-motta17-rhf-c2 for the RHF files.",
          "source_entry": "h-motta17-uhf-c2#40 (qmbl-verify 2026-10-23/24, correction; skeptic upheld)"
        },
        {
          "field": "sampled",
          "to": false,
          "reported_as": "-25.694342 (total for N = 50)",
          "location": "dataset github.com/simonsfoundation/hydrogen-benchmark-PRX, commit b99a183 (2017-10-09, uploaded by the authors), CC BY 4.0, file N_50_OBC/R_1.4/UHF_basis-TZ in sources/1705.01608-data-b99a183.tsv; number first printed in the dataset (RULES.md §8), the paper is the method reference",
          "checked_on": "2026-10-20",
          "reason": "Deterministic, not a Monte Carlo estimate, as the track-3 reader recorded it (pass row `sampled`); the method string alone reads the other way (units.mjs, isSampled).",
          "source_entry": "passes/track3/sweep-rows-2026-10-20-hydrogen.json"
        }
      ]
    }
  ],
  "url": "https://qmbl.org/i/Hchain/chain_50_O_R1.4_ccpvtz/",
  "per_site_divisor": 50,
  "per_site_label": "E/N (Ha)",
  "best": {
    "exact": null,
    "variational": {
      "energy": -25.694342,
      "sigma": null,
      "method": "HF",
      "ansatz": null,
      "method_detail": "unrestricted, basis vectors with overlap eigenvalue below 1e-7 removed (near linear dependence; Appendix A.1)",
      "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
      "bound_type": "variational",
      "energy_per_site": -0.51388684
    },
    "projected": {
      "energy": -27.0317,
      "sigma": 0.0016,
      "method": "ph-AFQMC",
      "ansatz": null,
      "method_detail": "",
      "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
      "bound_type": "projected",
      "energy_per_site": -0.5406340000000001
    },
    "extrapolated": null,
    "approximate": {
      "energy": -27.01495,
      "sigma": null,
      "method": "RCCSD(T)",
      "ansatz": null,
      "method_detail": "",
      "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
      "bound_type": "approximate",
      "energy_per_site": -0.540299
    },
    "below_exact": []
  },
  "no_best_reason": null,
  "record": {
    "energy": -27.0317,
    "sigma": 0.0016,
    "method": "ph-AFQMC",
    "ansatz": null,
    "method_detail": "",
    "reference": "M. Motta, D. M. Ceperley, G. K.-L. Chan, J. A. Gomez, E. Gull, S. Guo, C. A. Jiménez-Hoyos, T. N. Lan, J. Li, F. Ma, A. J. Millis, N. V. Prokof’ev, U. Ray, G. E. Scuseria, S. Sorella, E. M. Stoudenmire, Q. Sun, I. S. Tupitsyn, S. R. White, D. Zgid & S. Zhang, Towards the Solution of the Many-Electron Problem in Real Materials: Equation of State of the Hydrogen Chain with State-of-the-Art Many-Body Methods, Phys. Rev. X 7, 031059 (2017), arXiv:1705.01608, doi:10.1103/PhysRevX.7.031059",
    "bound_type": "projected",
    "energy_per_site": -0.5406340000000001
  },
  "no_record_reason": null
}