Method
- Mapper
- PT
- Ansatz
- UCC
- Optimizer
- COBYLA
- Maximum iterations
- 40
- Best energy (Ha)
- -5.01764
O2
BeyondH2 hardware VQE and fixed-parameter remeasurement · hardware · ibm_pittsburgh
Final energy-4.7721321508hartree
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
- 2026-08-02T16:05:09+00:00
- Wall time (s)
- 877.382
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)
- 0.590517
- Signed error (Ha)
- 0.590517
- Total QPU time (s)
- 150
- Calibration time
- 2026-08-02T15:20:42+00:00
- Mean readout error
- 0.005096435546875
- 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
25 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 | -4.8709958182 | 31.4324 | 6 | [0.0] |
| 2 | succeeded | -4.3244064255 | 31.3246 | 6 | [1.0] |
| 3 | succeeded | -4.0819156040 | 31.1809 | 6 | [-1.0] |
| 4 | succeeded | -4.8296693312 | 31.3148 | 6 | [0.5] |
| 5 | succeeded | -4.8683255847 | 31.3763 | 6 | [-0.25] |
| 6 | succeeded | -4.9630316868 | 31.3011 | 6 | [0.1] |
| 7 | succeeded | -4.8764250291 | 31.233 | 6 | [0.30000000000000004] |
| 8 | succeeded | -4.7125545685 | 31.2948 | 6 | [0.0] |
| 9 | succeeded | -4.9732358717 | 31.2629 | 6 | [0.2] |
| 10 | succeeded | -4.8676398425 | 31.015 | 6 | [0.30000000000000004] |
| 11 | succeeded | -5.0146425631 | 61.2792 | 6 | [0.15] |
| 12 | succeeded | -4.7057699600 | 31.5228 | 6 | [0.049999999999999975] |
| 13 | succeeded | -4.9618295245 | 31.3568 | 6 | [0.2] |
| 14 | succeeded | -4.9919878566 | 61.3997 | 6 | [0.13749999999999998] |
| 15 | succeeded | -4.9214002862 | 31.1361 | 6 | [0.175] |
| 16 | succeeded | -4.9146372359 | 31.0167 | 6 | [0.13999999999999999] |
| 17 | succeeded | -5.0139743834 | 61.6397 | 6 | [0.16] |
| 18 | succeeded | -4.9325579255 | 31.3045 | 6 | [0.145] |
| 19 | succeeded | -5.0176442711 | 31.1033 | 6 | [0.1525] |
| 20 | succeeded | -4.9875469964 | 31.1202 | 6 | [0.1535] |
| 21 | succeeded | -4.8214946334 | 31.0174 | 6 | [0.1515] |
| 22 | succeeded | -5.0064394839 | 31.0629 | 6 | [0.153] |
| 23 | succeeded | -4.9302418985 | 31.077 | 6 | [0.15225] |
| 24 | succeeded | -5.0073844241 | 31.1044 | 6 | [0.15259999999999999] |
| 25 | succeeded | -4.7721321508 | 31.4897 | 6 | [0.1524] |
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 | -5.0210106535 | -5.0795565432 | -4.9470044373 | 28 |
| theta_best | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -5.0318452246 | -5.0522857542 | -5.0202140183 | 12 |
| theta_best | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -5.0558073440 | -5.0917357311 | -5.0182529494 | 38.4 |
| theta_best | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.9728540157 | -5.0008100468 | -4.9568552237 | 15.9 |
| theta_best | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.2818957599 | -5.3193137121 | -5.2369245927 | 41.7 |
| theta_final | EPOCH-2B4918A2E64142FB | 1024 | 0 | 7 | -5.0118416911 | -5.0502159408 | -4.9459059664 | 28 |
| theta_final | EPOCH-5882C2993A675671 | 1024 | 0 | 3 | -5.0419299367 | -5.0455431202 | -5.0398086806 | 12 |
| theta_final | EPOCH-5A5B8E676A712361 | 1024 | 0 | 10 | -5.0563196556 | -5.0990210235 | -5.0036059220 | 38.4 |
| theta_final | EPOCH-DE16026B7C747E84 | 1024 | 1 | 3 | -4.9609983011 | -5.0218576937 | -4.8842828427 | 15.9 |
| theta_final | EPOCH-EB7658141BD7F934 | 1024 | 2 | 3 | -5.2268864355 | -5.2420496568 | -5.2186520067 | 41.7 |
Means below combine the displayed measurements descriptively. Inspect epochs and replicates in the download before drawing statistical conclusions.