{
  "counts": {
    "above_hull": 19,
    "entries": 96,
    "intervals": 8,
    "vertices": 9
  },
  "elements": [
    "CO",
    "ER"
  ],
  "flags": [
    "has_intermediate_compounds",
    "mp_agreement_not_comparable",
    "theoretical_vertices"
  ],
  "isotherms": [
    {
      "intervals": [
        {
          "intercept": 0.0,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-594128",
            "x": 0.0
          },
          "mu_a_rel": 0.0,
          "mu_b_rel": -1.1435411399999966,
          "right": {
            "phase": "oqmd-1280453",
            "x": 0.10526315789473684
          },
          "slope": -1.1435411399999966,
          "x_hi": 0.10526315789473684,
          "x_lo": 0.0
        },
        {
          "intercept": -0.05020485464285636,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-1280453",
            "x": 0.10526315789473684
          },
          "mu_a_rel": -0.05020485464285636,
          "mu_b_rel": -0.7167998755357176,
          "right": {
            "phase": "oqmd-1280595",
            "x": 0.20689655172413793
          },
          "slope": -0.6665950208928612,
          "x_hi": 0.20689655172413793,
          "x_lo": 0.10526315789473684
        },
        {
          "intercept": -0.060849282000001836,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-1280595",
            "x": 0.20689655172413793
          },
          "mu_a_rel": -0.060849282000001836,
          "mu_b_rel": -0.6759962373333265,
          "right": {
            "phase": "oqmd-113163",
            "x": 0.25
          },
          "slope": -0.6151469553333246,
          "x_hi": 0.25,
          "x_lo": 0.20689655172413793
        },
        {
          "intercept": -0.10295746333333403,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-113163",
            "x": 0.25
          },
          "mu_a_rel": -0.10295746333333403,
          "mu_b_rel": -0.5496716933333299,
          "right": {
            "phase": "oqmd-29233",
            "x": 0.3333333333333333
          },
          "slope": -0.4467142299999959,
          "x_hi": 0.3333333333333333,
          "x_lo": 0.25
        },
        {
          "intercept": -0.25181291999999794,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-29233",
            "x": 0.3333333333333333
          },
          "mu_a_rel": -0.25181291999999794,
          "mu_b_rel": -0.25196078000000205,
          "right": {
            "phase": "oqmd-1375335",
            "x": 0.5
          },
          "slope": -0.00014786000000410746,
          "x_hi": 0.5,
          "x_lo": 0.3333333333333333
        },
        {
          "intercept": -0.35172348166666845,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-1375335",
            "x": 0.5
          },
          "mu_a_rel": -0.35172348166666845,
          "mu_b_rel": -0.1520502183333316,
          "right": {
            "phase": "oqmd-1484196",
            "x": 0.7142857142857143
          },
          "slope": 0.19967326333333685,
          "x_hi": 0.7142857142857143,
          "x_lo": 0.5
        },
        {
          "intercept": -0.558641539999984,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-1484196",
            "x": 0.7142857142857143
          },
          "mu_a_rel": -0.558641539999984,
          "mu_b_rel": -0.06928299500000534,
          "right": {
            "phase": "oqmd-690190",
            "x": 0.75
          },
          "slope": 0.48935854499997866,
          "x_hi": 0.75,
          "x_lo": 0.7142857142857143
        },
        {
          "intercept": -0.766490525,
          "kind": "two_phase",
          "left": {
            "phase": "oqmd-690190",
            "x": 0.75
          },
          "mu_a_rel": -0.766490525,
          "mu_b_rel": 0.0,
          "right": {
            "phase": "oqmd-ref-Er",
            "x": 1.0
          },
          "slope": 0.766490525,
          "x_hi": 1.0,
          "x_lo": 0.75
        }
      ],
      "temperature_K": 0.0,
      "vertices": [
        {
          "collinear": false,
          "degenerate": [],
          "energy": 0.0,
          "energy_per_atom": -7.089565,
          "entries_at_x": 38,
          "formula": "Co1",
          "nsites": 1,
          "phase": "oqmd-594128",
          "phase_kind": "structure",
          "spacegroup_number": 225,
          "spacegroup_symbol": "Fm-3m",
          "theoretical": false,
          "x": 0.0
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.120372751578947,
          "energy_per_atom": -6.94401938842105,
          "entries_at_x": 2,
          "formula": "Co17 Er2",
          "nsites": 19,
          "phase": "oqmd-1280453",
          "phase_kind": "structure",
          "spacegroup_number": 166,
          "spacegroup_symbol": "R-3m",
          "theoretical": true,
          "x": 0.10526315789473684
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.188121065862069,
          "energy_per_atom": -6.75501893827586,
          "entries_at_x": 1,
          "formula": "Co23 Er6",
          "nsites": 29,
          "phase": "oqmd-1280595",
          "phase_kind": "structure",
          "spacegroup_number": 225,
          "spacegroup_symbol": "Fm-3m",
          "theoretical": true,
          "x": 0.20689655172413793
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.214636020833333,
          "energy_per_atom": -6.67264490833333,
          "entries_at_x": 6,
          "formula": "Co3 Er1",
          "nsites": 12,
          "phase": "oqmd-113163",
          "phase_kind": "structure",
          "spacegroup_number": 166,
          "spacegroup_symbol": "R-3m",
          "theoretical": false,
          "x": 0.25
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.251862206666666,
          "energy_per_atom": -6.49935239,
          "entries_at_x": 3,
          "formula": "Co2 Er1",
          "nsites": 6,
          "phase": "oqmd-29233",
          "phase_kind": "structure",
          "spacegroup_number": 227,
          "spacegroup_symbol": "Fd-3m",
          "theoretical": false,
          "x": 0.3333333333333333
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.25188685,
          "energy_per_atom": -6.078339625,
          "entries_at_x": 8,
          "formula": "Co1 Er1",
          "nsites": 4,
          "phase": "oqmd-1375335",
          "phase_kind": "structure",
          "spacegroup_number": 63,
          "spacegroup_symbol": "Cmcm",
          "theoretical": true,
          "x": 0.5
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.20909972214285638,
          "energy_per_atom": -5.494218686428572,
          "entries_at_x": 1,
          "formula": "Co2 Er5",
          "nsites": 14,
          "phase": "oqmd-1484196",
          "phase_kind": "structure",
          "spacegroup_number": 15,
          "spacegroup_symbol": "C2/c",
          "theoretical": true,
          "x": 0.7142857142857143
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": -0.19162263125,
          "energy_per_atom": -5.38651929375,
          "entries_at_x": 6,
          "formula": "Co1 Er3",
          "nsites": 16,
          "phase": "oqmd-690190",
          "phase_kind": "structure",
          "spacegroup_number": 62,
          "spacegroup_symbol": "Pnma",
          "theoretical": false,
          "x": 0.75
        },
        {
          "collinear": false,
          "degenerate": [],
          "energy": 0.0,
          "energy_per_atom": -4.563341,
          "entries_at_x": 19,
          "formula": "Er",
          "nsites": null,
          "phase": "oqmd-ref-Er",
          "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": 0.016891099999999604,
    "only_mp_stable": [
      "oqmd-51743",
      "oqmd-ref-Co"
    ],
    "only_ours_stable": [
      "oqmd-1280453",
      "oqmd-1484196"
    ],
    "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": "CO-ER",
  "x_element": "ER"
}
