Method
- Mapper
- P
- Ansatz
- UCC
- Optimizer
- COBYLA
- Maximum iterations
- 30
- Best energy (Ha)
- -0.806456
H2
H2 VQE accuracy-cost benchmark · hardware · ibm_brussels
Final energy-0.7542494925hartree
Shots1024
Runtime executionsession
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
- session
- Shots
- 1024
- Precision
- 0.03125
- Resilience
- 0
- Submitted
- 2026-01-19T23:45:21+01:00
- Wall time (s)
- 117
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)
- 1.10303
- Signed error (Ha)
- 1.10303
- Total QPU time (s)
- 28
- 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
18 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 | -0.8005016907 | 11.8832 | 4 | — |
| 2 | succeeded | -0.7946818764 | 8.55742 | 3 | — |
| 3 | succeeded | -0.7740460141 | 8.56792 | 2 | — |
| 4 | succeeded | -0.7697425205 | 7.18901 | 1 | — |
| 5 | succeeded | -0.7608721665 | 8.07832 | 3 | — |
| 6 | succeeded | -0.7859080415 | 8.15179 | 2 | — |
| 7 | succeeded | -0.7731184182 | 6.57989 | 2 | — |
| 8 | succeeded | -0.7882326528 | 5.57916 | 1 | — |
| 9 | succeeded | -0.7609372710 | 5.07481 | 1 | — |
| 10 | succeeded | -0.7340539637 | 5.76992 | 1 | — |
| 11 | succeeded | -0.7486794489 | 5.22087 | 1 | — |
| 12 | succeeded | -0.7610144379 | 5.41005 | 1 | — |
| 13 | succeeded | -0.8064555373 | 5.76228 | 1 | — |
| 14 | succeeded | -0.7467736541 | 5.59007 | 1 | — |
| 15 | succeeded | -0.7603301120 | 5.24443 | 1 | — |
| 16 | succeeded | -0.7824418553 | 5.0218 | 1 | — |
| 17 | succeeded | -0.7548050954 | 5.14441 | 1 | — |
| 18 | succeeded | -0.7542494925 | 5.15563 | 1 | — |