Entry HF_ccpvdz_BK_UCCSD_v4_tapered__sha256_42ad3163dd5bcf87 | QEncode

VQE Gap

1.4424e-11 Ha

CASCI ref

-100.019483 Ha

Qubits (tapered)

CCSD(T) corr.

-2.107e-1 Ha

Molecule / Problem

NameHF

Basis setcc-pvdz

GeometryH 0.0 0.0 0.0; F 0.0 0.0 0.917

Charge0

Spin0

Active electrons2

Active orbitals2

Orbital optimizationHF

Encoding / Circuit

Qubit mappingbravyi-kitaev

Ansatz typeuccsd_tapered

Ansatz reps (HEA)1

TaperingZ2 symmetry — 3 symmetries removed

Qubits (original)4

Qubits (tapered)1

Num parameters1

Circuit depth2

2Q gates0

Note on UCCSD circuit metrics

UCCSD uses exponential Pauli operators (exp(iθH)) that are symbolic before compilation. Circuit depth and 2-qubit gate counts are not reported here — they depend on the target hardware and transpiler.

Energy Results

HF energy-100.0194112692 Ha

MP2 energy-100.2231931799 Ha

CCSD energy-100.2281549564 Ha

CCSD(T) energy-100.2300913457 Ha

CASCI ground state-100.0194827962 Ha

VQE best energy-100.0194827962 Ha

|VQE − CASCI| gap1.442402e-11 Ha

CCSD(T) correlation-2.106801e-1 Ha

Optimizer / Run Config

AlgorithmCOBYLA

Multistart runs10

Max iterations500

Total func evals220

Num parameters1

Backenddefault.qubit

Provenance / Reproducibility

Entry IDHF_ccpvdz_BK_UCCSD_v4_tapered__sha256_42ad3163dd5bcf87

Schema version4.0.0

Created (UTC)2026-07-15T13:22:32.206794+00:00

SHA-256 hash42ad3163dd5bcf87c0fb1fb21662345b4dbb8cf015007d0cdab5f190f920a2e0

Python3.11.15

PySCF2.6.2

PennyLane0.45.0

OpenFermion1.6.1

NumPy2.2.6

SciPy1.13.1

Reproduce this result

# Clone repo and install pinned environment

git clone https://github.com/qencode-benchmark/qencode-benchmark

cd qencode-benchmark

pip install -r requirements-v4.txt

# Run this entry

python scripts/generate_entry_v4.py \

--molecule HF \

--mapping bravyi_kitaev \

--ansatz-type uccsd \

--multistart 10 \

--max-iter 500 \

--out-dir releases/v4/db

View raw JSON on GitHub