Method
- Mapper
- PT
- Ansatz
- UCC
- Optimizer
- COBYLA
- Maximum iterations
- 40
- Best energy (Ha)
- -4.9044
O2
BeyondH2 hardware VQE and fixed-parameter remeasurement · hardware · ibm_pittsburgh
Final energy-4.8085532708hartree
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
- 2026-08-02T18:57:04+00:00
- Wall time (s)
- 2391.05
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)
- 0.554096
- Signed error (Ha)
- 0.554096
- Total QPU time (s)
- 132
- Calibration time
- 2026-08-02T17:28:21+00:00
- Mean readout error
- 0.004913330078125
- 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 | -4.7892633034 | 31.4126 | 6 | [0.0] |
| 2 | succeeded | -4.3667792913 | 31.1634 | 6 | [1.0] |
| 3 | succeeded | -4.0958421385 | 61.6465 | 6 | [-1.0] |
| 4 | succeeded | -4.8116193931 | 61.5654 | 6 | [0.5] |
| 5 | succeeded | -4.4914778053 | 1577.01 | 6 | [0.75] |
| 6 | succeeded | -4.8211367166 | 61.6996 | 6 | [0.4] |
| 7 | succeeded | -4.7339211129 | 30.9163 | 6 | [0.30000000000000004] |
| 8 | succeeded | -4.8917208751 | 31.3247 | 6 | [0.45] |
| 9 | succeeded | -4.7992466387 | 31.718 | 6 | [0.55] |
| 10 | succeeded | -4.8551001125 | 31.1218 | 6 | [0.4] |
| 11 | succeeded | -4.7518829455 | 31.1202 | 6 | [0.47500000000000003] |
| 12 | succeeded | -4.8396356890 | 31.2334 | 6 | [0.445] |
| 13 | succeeded | -4.8390876968 | 31.5162 | 6 | [0.46] |
| 14 | succeeded | -4.8409675500 | 61.3162 | 6 | [0.445] |
| 15 | succeeded | -4.8780712218 | 31.5247 | 6 | [0.4525] |
| 16 | succeeded | -4.9043971200 | 30.9766 | 6 | [0.449] |
| 17 | succeeded | -4.8221038345 | 61.8343 | 6 | [0.447] |
| 18 | succeeded | -4.8396384185 | 31.4087 | 6 | [0.45] |
| 19 | succeeded | -4.5956340506 | 31.2464 | 6 | [0.4485] |
| 20 | succeeded | -4.7919115498 | 31.3415 | 6 | [0.44925] |
| 21 | succeeded | -4.5046350904 | 31.4238 | 6 | [0.4489] |
| 22 | succeeded | -4.8085532708 | 31.0751 | 6 | [0.4491] |
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 | -4.8341946310 | -4.8765156302 | -4.7785075485 | 28 |
| theta_best | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -4.8385506427 | -4.8432232267 | -4.8350552419 | 12 |
| theta_best | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -4.8506510352 | -4.8923521029 | -4.8347829772 | 38.4 |
| theta_best | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.7789793669 | -4.8193633880 | -4.7283161779 | 15.9 |
| theta_best | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.0443967336 | -5.0713846213 | -5.0292526318 | 41.7 |
| theta_final | EPOCH-2B4918A2E64142FB | 1024 | 0 | 7 | -4.8199952307 | -4.8628707611 | -4.7944239128 | 28 |
| theta_final | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -4.8285621666 | -4.8630455072 | -4.8086086353 | 12 |
| theta_final | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -4.8444219821 | -4.8919698834 | -4.8180403618 | 38.4 |
| theta_final | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.7605183288 | -4.8277457053 | -4.6907490031 | 15.9 |
| theta_final | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.0021379266 | -5.0671036906 | -4.9666110946 | 41.7 |
Means below combine the displayed measurements descriptively. Inspect epochs and replicates in the download before drawing statistical conclusions.