QEncode Benchmark
Back to leaderboard

NH3

/jordan wigner/hea
Certified
Beats CCSD(T)
cc-pvdz

NH3_ccpvdz_JW_HEA_v4_tapered__sha256_07291783190d6a4e

VQE Gap

1.8800e-3 Ha

CASCI ref

-56.197889 Ha

Qubits (tapered)

5

CCSD(T) corr.

-2.085e-1 Ha

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 typehea
Ansatz reps (HEA)2
TaperingZ2 symmetry — 3 symmetries removed
Qubits (original)8
Qubits (tapered)5
Num parameters15
Circuit depth10
2Q gates8

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-56.1960085701 Ha
|VQE − CASCI| gap1.880019e-3 Ha
CCSD(T) correlation-2.085498e-1 Ha

Optimizer / Run Config

AlgorithmCOBYLA
Multistart runs1
Max iterations500
Total func evals500
Num parameters15
Backenddefault.qubit

Provenance / Reproducibility

Entry IDNH3_ccpvdz_JW_HEA_v4_tapered__sha256_07291783190d6a4e
Schema version4.0.0
Created (UTC)2026-07-15T13:21:49.954236+00:00
SHA-256 hash07291783190d6a4ebde62329dabbccc9c643bca9517c3136c93a208710cc0fa2
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 hea \

--reps 2 \

--multistart 1 \

--max-iter 500 \

--out-dir releases/v4/db