Entry NH3_ccpvdz_JW_UCCSD_v4_tapered__sha256_bff85ae0c8311f46 | QEncode

Molecule / Problem

NameNH3

Basis setcc-pvdz

GeometryN 0.0 0.0 0.1173; H 0.0 0.9289 -0.2737; H 0.8045 -0.4645 -0.2737; H -0.8045 -0.4645 -0.2737

Charge0

Spin0

Active electrons4

Active orbitals4

Orbital optimizationHF

Encoding / Circuit

Qubit mappingjordan-wigner

Ansatz typeuccsd_tapered

Ansatz reps (HEA)1

TaperingZ2 symmetry — 3 symmetries removed

Qubits (original)8

Qubits (tapered)5

Num parameters64

Circuit depth120

2Q gates24

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-56.1957314939 Ha

MP2 energy-56.3845132569 Ha

CCSD energy-56.4004649816 Ha

CCSD(T) energy-56.4042812742 Ha

CASCI ground state-56.1978885887 Ha

VQE best energy-56.1978561435 Ha

|VQE − CASCI| gap3.244515e-5 Ha

CCSD(T) correlation-2.085498e-1 Ha

Optimizer / Run Config

AlgorithmCOBYLA

Multistart runs1

Max iterations500

Total func evals500

Num parameters64

Backenddefault.qubit

Provenance / Reproducibility

Entry IDNH3_ccpvdz_JW_UCCSD_v4_tapered__sha256_bff85ae0c8311f46

Schema version4.0.0

Created (UTC)2026-07-15T13:22:23.704023+00:00

SHA-256 hashbff85ae0c8311f460149c33ceccd60b01fca644f3aea689401b6c3991bf463da

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 NH3 \

--mapping jordan_wigner \

--ansatz-type uccsd \

--multistart 1 \

--max-iter 500 \

--out-dir releases/v4/db

View raw JSON on GitHub