Method
- Mapper
- PT
- Ansatz
- UCC
- Optimizer
- COBYLA
- Maximum iterations
- 40
- Best energy (Ha)
- -4.87964
O2
BeyondH2 hardware VQE and fixed-parameter remeasurement · hardware · ibm_pittsburgh
Final energy-4.8386202905hartree
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
- 2026-08-01T18:56:28+00:00
- Wall time (s)
- 786.597
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)
- 0.524029
- Signed error (Ha)
- 0.524029
- Total QPU time (s)
- 132
- Calibration time
- 2026-08-01T18:35:13+00:00
- Mean readout error
- 0.00543212890625
- Mean two-qubit gate error
- 0.0033154795819567984
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 | -4.7379610045 | 61.6871 | 6 | [0.0] |
| 2 | succeeded | -4.3108391301 | 61.8816 | 6 | [1.0] |
| 3 | succeeded | -4.0850420095 | 31.6487 | 6 | [-0.9999999999999999] |
| 4 | succeeded | -4.4114789940 | 31.1884 | 6 | [0.5] |
| 5 | succeeded | -4.8224847221 | 31.4303 | 6 | [-0.25] |
| 6 | succeeded | -4.5854997752 | 31.4743 | 6 | [-0.5] |
| 7 | succeeded | -4.5456889503 | 31.2245 | 6 | [-0.14999999999999997] |
| 8 | succeeded | -4.4769508103 | 31.1552 | 6 | [-0.35] |
| 9 | succeeded | -4.8345616780 | 31.5277 | 6 | [-0.2] |
| 10 | succeeded | -4.8044428979 | 61.4682 | 6 | [-0.17500000000000002] |
| 11 | succeeded | -4.8702005109 | 31.4975 | 6 | [-0.21000000000000002] |
| 12 | succeeded | -4.8413438384 | 31.4324 | 6 | [-0.23000000000000004] |
| 13 | succeeded | -4.8258198711 | 31.3834 | 6 | [-0.2] |
| 14 | succeeded | -4.8418050162 | 31.051 | 6 | [-0.21500000000000002] |
| 15 | succeeded | -4.4429008094 | 31.3114 | 6 | [-0.20750000000000002] |
| 16 | succeeded | -4.8257003998 | 31.3264 | 6 | [-0.21050000000000002] |
| 17 | succeeded | -4.8660854143 | 31.1933 | 6 | [-0.20900000000000002] |
| 18 | succeeded | -4.8436941191 | 31.1328 | 6 | [-0.21050000000000002] |
| 19 | succeeded | -4.8664274880 | 31.2245 | 6 | [-0.20975000000000002] |
| 20 | succeeded | -4.5327373648 | 31.1054 | 6 | [-0.2101] |
| 21 | succeeded | -4.8796412462 | 31.3987 | 6 | [-0.20990000000000003] |
| 22 | succeeded | -4.8386202905 | 31.9402 | 6 | [-0.20980000000000004] |
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 | -5.0011585957 | -5.0486203359 | -4.9410718622 | 28 |
| theta_best | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -5.0057721595 | -5.0111130633 | -4.9988755141 | 12 |
| theta_best | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -5.0355398688 | -5.0712945433 | -4.9924748871 | 38.4 |
| theta_best | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.9707218112 | -5.0004539538 | -4.9292479469 | 15.9 |
| theta_best | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.2482222326 | -5.2777152613 | -5.2313717566 | 41.7 |
| theta_final | EPOCH-2B4918A2E64142FB | 1024 | 0 | 7 | -5.0026056564 | -5.0500147699 | -4.9310987515 | 28 |
| theta_final | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -5.0052068677 | -5.0099148331 | -4.9960081190 | 12 |
| theta_final | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -5.0310261350 | -5.0648865011 | -4.9967211620 | 38.4 |
| theta_final | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.9658824795 | -5.0156892424 | -4.9018570579 | 15.9 |
| theta_final | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.2575598966 | -5.3152802280 | -5.1914623206 | 41.7 |
Means below combine the displayed measurements descriptively. Inspect epochs and replicates in the download before drawing statistical conclusions.