{
  "counts": {
    "above_hull": 38,
    "entries": 106,
    "intervals": 7,
    "vertices": 8
  },
  "elements": [
    "CA",
    "NI"
  ],
  "flags": [
    "has_intermediate_compounds",
    "mp_agreement_not_comparable",
    "theoretical_vertices"
  ],
  "isotherms": [
    {
      "intervals": [
        {
          "intercept": 0.0,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-594524",
            "x": 0.0
          },
          "mu_a_rel": 0.0,
          "mu_b_rel": -0.44519620250000097,
          "right": {
            "phase": "oqmd-1377855",
            "x": 0.3333333333333333
          },
          "slope": -0.44519620250000097,
          "x_hi": 0.3333333333333333,
          "x_lo": 0.0
        },
        {
          "intercept": -0.0876295106250005,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-1377855",
            "x": 0.3333333333333333
          },
          "mu_a_rel": -0.0876295106250005,
          "mu_b_rel": -0.26993718125,
          "right": {
            "phase": "oqmd-2168865",
            "x": 0.6
          },
          "slope": -0.18230767062499947,
          "x_hi": 0.6,
          "x_lo": 0.3333333333333333
        },
        {
          "intercept": -0.16602231749999957,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-2168865",
            "x": 0.6
          },
          "mu_a_rel": -0.16602231749999957,
          "mu_b_rel": -0.21767531000000062,
          "right": {
            "phase": "oqmd-2066421",
            "x": 0.6666666666666666
          },
          "slope": -0.051652992500001035,
          "x_hi": 0.6666666666666666,
          "x_lo": 0.6
        },
        {
          "intercept": -0.3104216624999971,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-2066421",
            "x": 0.6666666666666666
          },
          "mu_a_rel": -0.3104216624999971,
          "mu_b_rel": -0.14547563750000184,
          "right": {
            "phase": "oqmd-2160268",
            "x": 0.7222222222222222
          },
          "slope": 0.16494602499999525,
          "x_hi": 0.7222222222222222,
          "x_lo": 0.6666666666666666
        },
        {
          "intercept": -0.468284075000014,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-2160268",
            "x": 0.7222222222222222
          },
          "mu_a_rel": -0.468284075000014,
          "mu_b_rel": -0.08475932499999533,
          "right": {
            "phase": "oqmd-28964",
            "x": 0.75
          },
          "slope": 0.3835247500000187,
          "x_hi": 0.75,
          "x_lo": 0.7222222222222222
        },
        {
          "intercept": -0.6966216350000024,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-28964",
            "x": 0.75
          },
          "mu_a_rel": -0.6966216350000024,
          "mu_b_rel": -0.008646804999999147,
          "right": {
            "phase": "oqmd-2026083",
            "x": 0.7777777777777778
          },
          "slope": 0.6879748300000033,
          "x_hi": 0.7777777777777778,
          "x_lo": 0.75
        },
        {
          "intercept": -0.7268854524999995,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-2026083",
            "x": 0.7777777777777778
          },
          "mu_a_rel": -0.7268854524999995,
          "mu_b_rel": 1.1102230246251565e-16,
          "right": {
            "phase": "oqmd-ref-Ni",
            "x": 1.0
          },
          "slope": 0.7268854524999996,
          "x_hi": 1.0,
          "x_lo": 0.7777777777777778
        }
      ],
      "temperature_K": 0.0,
      "vertices": [
        {
          "collinear": false,
          "degenerate": [],
          "energy": 0.0,
          "energy_per_atom": -1.977817,
          "entries_at_x": 31,
          "formula": "Ca1",
          "nsites": 1,
          "phase": "oqmd-594524",
          "phase_kind": "structure",
          "spacegroup_number": 225,
          "spacegroup_symbol": "Fm-3m",
          "theoretical": false,
          "x": 0.0
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.148398734166667,
          "energy_per_atom": -3.3224832408333334,
          "entries_at_x": 5,
          "formula": "Ca2 Ni1",
          "nsites": 12,
          "phase": "oqmd-1377855",
          "phase_kind": "structure",
          "spacegroup_number": 62,
          "spacegroup_symbol": "Pnma",
          "theoretical": true,
          "x": 0.3333333333333333
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.19701411300000019,
          "energy_per_atom": -4.328112625,
          "entries_at_x": 3,
          "formula": "Ca2 Ni3",
          "nsites": 10,
          "phase": "oqmd-2168865",
          "phase_kind": "structure",
          "spacegroup_number": 14,
          "spacegroup_symbol": "P21/c",
          "theoretical": true,
          "x": 0.6
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.2004576458333336,
          "energy_per_atom": -4.570809659166667,
          "entries_at_x": 3,
          "formula": "Ca1 Ni2",
          "nsites": 24,
          "phase": "oqmd-2066421",
          "phase_kind": "structure",
          "spacegroup_number": 194,
          "spacegroup_symbol": "P63/mmc",
          "theoretical": true,
          "x": 0.6666666666666666
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.1912939777777783,
          "energy_per_atom": -4.761023908888889,
          "entries_at_x": 1,
          "formula": "Ca5 Ni13",
          "nsites": 18,
          "phase": "oqmd-2160268",
          "phase_kind": "structure",
          "spacegroup_number": 166,
          "spacegroup_symbol": "R-3m",
          "theoretical": true,
          "x": 0.7222222222222222
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.1806405125,
          "energy_per_atom": -4.8500594025,
          "entries_at_x": 5,
          "formula": "Ca1 Ni3",
          "nsites": 12,
          "phase": "oqmd-28964",
          "phase_kind": "structure",
          "spacegroup_number": 166,
          "spacegroup_symbol": "R-3m",
          "theoretical": false,
          "x": 0.75
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.16153010055555544,
          "energy_per_atom": -4.930637949444444,
          "entries_at_x": 1,
          "formula": "Ca2 Ni7",
          "nsites": 18,
          "phase": "oqmd-2026083",
          "phase_kind": "structure",
          "spacegroup_number": 166,
          "spacegroup_symbol": "R-3m",
          "theoretical": true,
          "x": 0.7777777777777778
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": 0.0,
          "energy_per_atom": -5.56662,
          "entries_at_x": 29,
          "formula": "Ni",
          "nsites": null,
          "phase": "oqmd-ref-Ni",
          "phase_kind": "structure",
          "spacegroup_number": null,
          "spacegroup_symbol": "",
          "theoretical": false,
          "x": 1.0
        }
      ]
    }
  ],
  "mp_agreement": {
    "comparable": false,
    "comparable_note": "is_stable is derived by the extraction, not an upstream flag, so comparing it against a hull recomputed from the same energies tests the derivation rather than the data",
    "max_abs_delta_energy_above_hull": 0.0017020512500005719,
    "only_mp_stable": [
      "oqmd-ref-Ca"
    ],
    "only_ours_stable": [
      "oqmd-2026083",
      "oqmd-2066421",
      "oqmd-28964"
    ],
    "stable_sets_match": false
  },
  "provenance": {
    "above_hull_window_eV": 0.05,
    "builder_version": 1,
    "collinear_tol": 1e-12,
    "correction_model": "OQMD fit-partial ('standard' fit, applied upstream by OQMD; none added)",
    "degenerate_tol": 1e-06,
    "entry_pool": "all_nondeprecated",
    "is_stable_source": "derived",
    "observed_at": "2026-09-05T17:02:03Z",
    "snapshot_scope_elements": [],
    "snapshot_scope_kind": "full",
    "snapshot_sha256": "2a9393262c52ec35600424236c352a4cdb3291c8b25c1c6588f5e62abe8e0d8d",
    "source_release": "qmdb_v1_8_022026",
    "stability_tol": 0.0001,
    "thermo_type": "standard",
    "upstream_energy_corrections": "OQMD 'standard' fit (fit-partial of Kirklin et al. 2015): elemental reference energies of a subset of elements fitted to experimental formation enthalpies, applied by OQMD"
  },
  "reference": {
    "kind": "dft_fitted_elemental_reference_0K",
    "per": "atom",
    "temperature_K": 0.0,
    "units": "eV/atom"
  },
  "schema_version": 1,
  "system_id": "CA-NI",
  "x_element": "NI"
}
