Entry HF_ccpvdz_JW_UCCSD_v4_tapered__sha256_65500d662073f9e4 | QEncode

VQE Gap

1.8267e-9 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 mappingjordan-wigner

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-100.0194827944 Ha

|VQE − CASCI| gap1.826692e-9 Ha

CCSD(T) correlation-2.106801e-1 Ha

Optimizer / Run Config

AlgorithmCOBYLA

Multistart runs1

Max iterations500

Total func evals20

Num parameters1

Backenddefault.qubit

Provenance / Reproducibility

Entry IDHF_ccpvdz_JW_UCCSD_v4_tapered__sha256_65500d662073f9e4

Schema version4.0.0

Created (UTC)2026-07-15T13:22:35.017395+00:00

SHA-256 hash65500d662073f9e464922e4a50a22dc529d951a9b2d7ce945cc6fd53cf32278c

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 jordan_wigner \

--ansatz-type uccsd \

--multistart 1 \

--max-iter 500 \

--out-dir releases/v4/db

View raw JSON on GitHub