Method
- Mapper
- P
- Ansatz
- UCC
- Optimizer
- COBYLA
- Maximum iterations
- 30
- Best energy (Ha)
- -0.906777
H2
H2 VQE accuracy-cost benchmark · hardware · ibm_brussels
Final energy-0.8678879742hartree
Shots1024
Runtime executionsingle-job
Resilience0
MappingP
Active space2e,2o
Parity mapping without qubit reduction · Shots and precision · Resilience settings
Execution
- Mode
- hardware
- Provider
- IBM Quantum
- Compute resource
- ibm_brussels
- Resource type
- ibm quantum hardware
- Processor family
- Eagle r3
- Processor model
- Not recorded
- Processor revision
- Not recorded
- Qubits
- Not recorded
- Connectivity
- Not recorded
- Runtime execution
- single-job
- Shots
- 1024
- Precision
- 0.03125
- Resilience
- 0
- Submitted
- 2026-01-15T17:19:20+01:00
- Wall time (s)
- 121
Molecular system
- Charge
- 0
- Multiplicity
- 1
- Basis
- STO-3G
- Active space
- 2e,2o
- Active electrons
- 2
- Spatial orbitals
- 2
- Active orbital indices
- Not recorded
- Geometry units
- angstrom
Circuit
- Logical qubits
- 4
- Physical qubits
- Not recorded
- Parameters
- Not recorded
- Depth
- 74
- Two-qubit gates
- 32
- Hamiltonian terms
- Not recorded
Scientific provenance
- Cohort
- published h2
- Reference method
- exact diagonalization
- Reference energy (Ha)
- -1.85728
- Energy convention
- Published H2 benchmark electronic-energy convention
- Absolute error (Ha)
- 0.989387
- Signed error (Ha)
- 0.989387
- Total QPU time (s)
- 23
- Calibration time
- Not recorded
- Mean readout error
- Not recorded
- Mean two-qubit gate error
- Not recorded
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
- Qiskit Nature Pyscf
- 0.4.0
Molecular geometry (angstrom)
| Atom | x | y | z |
|---|---|---|---|
| H | 0 | 0 | 0 |
| H | 0 | 0 | 0.735 |
Dataset publication
Associated articles
- Accuracy-Cost Trade-offs for Reference VQE Calculations of H2 on IBM Quantum Hardware submitted to Quantum Science and Technology
- Accuracy-Cost Trade-offs for Reference VQE Calculations of H2 on IBM Quantum Hardware DOI 10.48550/arXiv.2604.11478 arXiv 2604.11478 published preprint
Compute access
- Fraunhofer Quantum Now and EQeS · IBM Quantum · allocation: Fraunhofer Quantum Now
Optimization trajectory
21 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 | -0.8180788554 | 6.90106 | 2 | — |
| 2 | succeeded | -0.8569611524 | 7.13055 | 1 | — |
| 3 | succeeded | -0.8392357369 | 6.51664 | 1 | — |
| 4 | succeeded | -0.8774727586 | 5.51624 | 1 | — |
| 5 | succeeded | -0.8929082431 | 6.02836 | 1 | — |
| 6 | succeeded | -0.8785044566 | 5.19219 | 1 | — |
| 7 | succeeded | -0.8994019519 | 5.50484 | 1 | — |
| 8 | succeeded | -0.8554408546 | 5.35427 | 1 | — |
| 9 | succeeded | -0.8648979173 | 5.33326 | 1 | — |
| 10 | succeeded | -0.8524971036 | 5.35233 | 1 | — |
| 11 | succeeded | -0.8638413214 | 5.30044 | 1 | — |
| 12 | succeeded | -0.8673757432 | 6.0816 | 1 | — |
| 13 | succeeded | -0.8917638701 | 5.89009 | 1 | — |
| 14 | succeeded | -0.8292000027 | 5.88927 | 1 | — |
| 15 | succeeded | -0.8652853177 | 5.47339 | 1 | — |
| 16 | succeeded | -0.9067767833 | 4.89251 | 1 | — |
| 17 | succeeded | -0.8717392483 | 5.19349 | 1 | — |
| 18 | succeeded | -0.8184283383 | 5.52301 | 1 | — |
| 19 | succeeded | -0.9034812663 | 6.00922 | 2 | — |
| 20 | succeeded | -0.8515097245 | 6.22343 | 1 | — |
| 21 | succeeded | -0.8678879742 | 5.26175 | 1 | — |