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20260727T225607Z-9108de

LIH · nvidia:fp64 · 10 qubits · 24 parameters · ansatz: matched

The UCCSD circuit spans exactly the (2e, 5o) active space the Hamiltonian lives on. With 2 active electrons, singles and doubles already cover the full CI space, so this parameterization is equivalent to FCI here.

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  "run_id": "20260727T225607Z-9108de",
  "project_name": "cudaq-molecular-simulation-blueprint",
  "project_version": "0.1.0",
  "created_at": "2026-07-27T22:56:08.037373Z",
  "completed_at": "2026-07-27T23:07:47.095611Z",
  "status": "completed",
  "backend": "gpu_fp64",
  "target_string": "nvidia:fp64",
  "seed": 45,
  "molecule": {
    "name": "lih",
    "geometry": [
      [
        "Li",
        [
          0.0,
          0.0,
          0.0
        ]
      ],
      [
        "H",
        [
          0.0,
          0.0,
          1.5957
        ]
      ]
    ],
    "basis": "sto-3g",
    "charge": 0,
    "multiplicity": 1,
    "active_electrons": 2,
    "active_orbitals": 5
  },
  "optimizer": {
    "name": "cobyla",
    "max_iterations": 1500,
    "tolerance": 1e-6,
    "initial_parameters": [
      -0.0457865206331563,
      -0.062285868215208595,
      0.01352900264295451,
      0.08439025938066932,
      -0.014849868815402095,
      0.026248378185626434,
      0.053166803805067255,
      0.06898072998697508,
      -0.08918986670310758,
      0.04688204243240465,
      -0.0017787628450144886,
      -0.06014296982866804,
      -0.06776350243759895,
      -0.022721533251618665,
      -0.09935554043352895,
      -0.1458902886878424,
      0.006375738341733588,
      0.07745178244115651,
      -0.024113170847950005,
      0.07400468968032174,
      -0.03999656033959914,
      -0.09953597301049023,
      -0.15222306549620349,
      -0.0820251460960864
    ]
  },
  "qubit_count": 10,
  "parameter_count": 24,
  "system_info": {
    "python_version": "3.11.0rc1",
    "platform": "Linux-5.15.0-185-generic-x86_64-with-glibc2.35",
    "machine": "x86_64",
    "processor": "x86_64",
    "cpu_count": 16,
    "cudaq_version": "0.14.2",
    "gpus": [
      {
        "name": "NVIDIA RTX PRO 6000 Blackwell Server Edition",
        "uuid": "GPU-dd54cb85-dcf0-0652-df41-7ab1531732d8",
        "driver_version": "580.173.02",
        "cuda_version": "13.0",
        "memory_total_mib": 97887
      }
    ],
    "git_sha": null
  },
  "result": {
    "energy": -7.882164029897012,
    "iterations": 1001,
    "parameters": [
      -0.0764603391771833,
      3.88106652506276e-7,
      -2.2361081312254874e-7,
      -0.007283117414725335,
      -0.07645601300123445,
      6.439751844062063e-8,
      -1.2038961891318312e-6,
      -0.007283940140141216,
      0.07191462071435012,
      -2.3320390563895975e-7,
      -8.737889199430173e-8,
      -0.1184661985649534,
      -2.805950428442655e-7,
      0.054869928499710015,
      -2.7300009165912163e-7,
      6.468983409935724e-9,
      3.0747137693226056e-7,
      5.567137742311092e-7,
      0.054890775829985125,
      -9.660519501251238e-7,
      -0.11876537370852751,
      -8.750615076191795e-8,
      -4.99176398604173e-7,
      0.2293142147655761
    ],
    "wall_time_seconds": 699.0267281850001,
    "converged": true,
    "reference_energy": -7.882164,
    "error_vs_reference_hartree": -2.989701197719796e-8,
    "chemical_accuracy_reached": true
  },
  "error": null,
  "notes": {
    "experiment": "lih_vqe",
    "experiment_variant": "lih_active_space_matched_ansatz_v02",
    "hamiltonian_terms": 276,
    "n_electrons": 4,
    "n_orbitals": 6,
    "bond_distance_angstrom": 1.5957,
    "reference": {
      "molecule": "lih",
      "basis": "sto-3g",
      "bond_distance_angstrom": 1.5957,
      "method": "CASCI(2e,5o) (pyscf 2026-05-04)",
      "energy_hartree": -7.882164,
      "note": "(2 active electrons, 5 active orbitals); freeze 1s of Li. Computed via pyscf.mcscf.CASCI(mf, 5, 2) on the RHF reference. Gap to full FCI at this geometry is only 0.227 mHa, so the active space captures essentially all of the FCI correlation."
    },
    "ansatz_name": "uccsd",
    "ansatz_mode": "matched",
    "ansatz_electron_count": 2,
    "ansatz_orbital_count": 5,
    "ansatz_qubit_count": 10,
    "ansatz_parameter_count": 24,
    "chemistry_reported_electron_count": 4,
    "chemistry_reported_orbital_count": 6,
    "active_electron_count": 2,
    "active_orbital_count": 5
  }
}

{
  "cpu_count": 16,
  "cudaq_version": "0.14.2",
  "git_sha": null,
  "gpus": [
    {
      "cuda_version": "13.0",
      "driver_version": "580.173.02",
      "memory_total_mib": 97887,
      "name": "NVIDIA RTX PRO 6000 Blackwell Server Edition",
      "uuid": "GPU-dd54cb85-dcf0-0652-df41-7ab1531732d8"
    }
  ],
  "machine": "x86_64",
  "platform": "Linux-5.15.0-185-generic-x86_64-with-glibc2.35",
  "processor": "x86_64",
  "python_version": "3.11.0rc1"
}