Method
- Mapper
- PT
- Ansatz
- UCC
- Optimizer
- COBYLA
- Maximum iterations
- 40
- Best energy (Ha)
- -4.983
O2
BeyondH2 hardware VQE and fixed-parameter remeasurement · hardware · ibm_pittsburgh
Final energy-4.9175008018hartree
Shots1024
Runtime executionsingle-job
Resilience0
MappingPT
Active space4e4o
Parity mapping with full symmetry tapering · Shots and precision · Resilience settings
Execution
- Mode
- hardware
- Provider
- IBM Quantum
- Compute resource
- ibm_pittsburgh
- Resource type
- quantum processor
- Processor family
- Heron
- Processor model
- ibm_pittsburgh
- Processor revision
- 3
- Qubits
- 156
- Connectivity
- Not recorded
- Runtime execution
- single-job
- Shots
- 1024
- Precision
- 0.03125
- Resilience
- 0
- Submitted
- 2026-08-02T07:22:40+00:00
- Wall time (s)
- 736.085
Molecular system
- Charge
- 0
- Multiplicity
- 3
- Basis
- sto3g
- Active space
- 4e4o
- Active electrons
- 4
- Spatial orbitals
- 4
- Active orbital indices
- Not recorded
- Geometry units
- angstrom
Circuit
- Logical qubits
- 4
- Physical qubits
- 4
- Parameters
- 1
- Depth
- 74
- Two-qubit gates
- 12
- Hamiltonian terms
- 50
Scientific provenance
- Cohort
- primary heron
- Reference method
- CASCI
- Reference energy (Ha)
- -5.362649434129489
- Energy convention
- Qiskit Nature active-space qubit Hamiltonian; nuclear and inactive-space constants excluded
- Absolute error (Ha)
- 0.445149
- Signed error (Ha)
- 0.445149
- Total QPU time (s)
- 132
- Calibration time
- 2026-08-02T06:39:56+00:00
- Mean readout error
- 0.00469970703125
- Mean two-qubit gate error
- 0.0034214190529237576
Software
- Qiskit
- 1.4.3
- Qiskit Aer
- 0.17.1
- Qiskit Algorithms
- 0.3.1
- Qiskit Ibm Runtime
- 0.40.1
- Qiskit Nature
- 0.7.2
Molecular geometry (angstrom)
| Atom | x | y | z |
|---|---|---|---|
| O | 0 | 0 | 0 |
| O | 0 | 0 | 1.216 |
Dataset publication
Associated articles
- The winner's curse in hardware VQE: drift-differenced remeasurement of finite-shot selection bias DOI 10.48550/arXiv.2609.27704 arXiv 2609.27704 published preprint
Compute access
- Fraunhofer Quantum Now and EQeS · IBM Quantum · allocation: Fraunhofer Quantum Now
Optimization trajectory
22 recorded objective evaluations. Charts use cumulative time so convergence cost remains comparable across calculations.
Download trajectory CSV · Download trajectory JSON
| Attempt | Outcome | Energy (Ha) | Elapsed (s) | Quantum (s) | Parameters |
|---|---|---|---|---|---|
| 1 | succeeded | -4.5038129455 | 31.7675 | 6 | [0.0] |
| 2 | succeeded | -4.2724523978 | 31.5302 | 6 | [1.0] |
| 3 | succeeded | -4.0540535265 | 32.3819 | 6 | [-1.0] |
| 4 | succeeded | -4.8189365382 | 31.5955 | 6 | [0.5] |
| 5 | succeeded | -3.8822664336 | 31.7378 | 6 | [1.5] |
| 6 | succeeded | -4.9681325704 | 31.9239 | 6 | [0.0] |
| 7 | succeeded | -4.6490384272 | 31.734 | 6 | [-0.5] |
| 8 | succeeded | -4.9829964974 | 31.8474 | 6 | [0.24999999999999994] |
| 9 | succeeded | -4.9090375522 | 31.4764 | 6 | [0.35] |
| 10 | succeeded | -4.9776799520 | 31.6597 | 6 | [0.14999999999999994] |
| 11 | succeeded | -4.9305648891 | 31.4783 | 6 | [0.29999999999999993] |
| 12 | succeeded | -4.9532585018 | 62.9029 | 6 | [0.22499999999999995] |
| 13 | succeeded | -4.9369497997 | 31.861 | 6 | [0.25999999999999995] |
| 14 | succeeded | -4.9237268384 | 31.6329 | 6 | [0.23999999999999994] |
| 15 | succeeded | -4.9732583886 | 31.4447 | 6 | [0.25499999999999995] |
| 16 | succeeded | -4.9664877483 | 31.9224 | 6 | [0.24749999999999994] |
| 17 | succeeded | -4.9044412860 | 31.5873 | 6 | [0.25099999999999995] |
| 18 | succeeded | -4.9497864261 | 31.7503 | 6 | [0.24899999999999994] |
| 19 | succeeded | -4.6036748338 | 31.7323 | 6 | [0.25049999999999994] |
| 20 | succeeded | -4.9775302827 | 31.6396 | 6 | [0.24974999999999994] |
| 21 | succeeded | -4.9735222998 | 31.6994 | 6 | [0.25009999999999993] |
| 22 | succeeded | -4.9175008018 | 31.7719 | 6 | [0.24989999999999996] |
Independent fixed-parameter remeasurements
These measurements reevaluate saved parameter vectors without running the optimizer. They are kept separate from the optimization trajectory.
| Vector | Epoch | Shots | Resilience | Measurements | Mean energy (Ha) | Minimum (Ha) | Maximum (Ha) | Allocated QPU time (s) |
|---|---|---|---|---|---|---|---|---|
| theta_best | EPOCH-2B4918A2E64142FB | 1024 | 0 | 7 | -4.9708555428 | -5.0178701828 | -4.9077196246 | 28 |
| theta_best | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -4.9989725609 | -5.0295646634 | -4.9700953470 | 12 |
| theta_best | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -5.0137148672 | -5.0558336621 | -4.9737598619 | 38.4 |
| theta_best | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.9228774113 | -4.9629405526 | -4.8612077473 | 15.9 |
| theta_best | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.1885340514 | -5.1993370926 | -5.1688794887 | 41.7 |
| theta_final | EPOCH-2B4918A2E64142FB | 1024 | 0 | 7 | -4.9654654303 | -5.0206105395 | -4.9028107474 | 28 |
| theta_final | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -4.9787068535 | -5.0005159731 | -4.9597227605 | 12 |
| theta_final | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -4.9958053179 | -5.0274867797 | -4.9614487328 | 38.4 |
| theta_final | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.9313365884 | -4.9728040349 | -4.8952803821 | 15.9 |
| theta_final | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.2261123748 | -5.2749126809 | -5.1625785366 | 41.7 |
Means below combine the displayed measurements descriptively. Inspect epochs and replicates in the download before drawing statistical conclusions.