Entry NH3_ccpvdz_PAR_HEA_v4_tapered__sha256_985901ca28fa7f97 | 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 mappingparity

Ansatz typehea

Ansatz reps (HEA)2

TaperingZ2 symmetry — 3 symmetries removed

Qubits (original)8

Qubits (tapered)5

Num parameters15

Circuit depth10

2Q gates8

Non-Clifford gates15

T gates (FT estimate)180 (ε = 0.001)

T-gate count is the resource-relevant cost of a fault-tolerant implementation. It is an estimate from the non-Clifford rotations in the pre-transpilation circuit, assuming standard rotation synthesis to precision ε — not a compiled count for a specific device.

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-56.1971545181 Ha

|VQE − CASCI| gap7.340706e-4 Ha

CCSD(T) correlation-2.085498e-1 Ha

Optimizer / Run Config

AlgorithmCOBYLA

Multistart runs3

Max iterations500

Total func evals1,500

Num parameters15

Backenddefault.qubit

Provenance / Reproducibility

Entry IDNH3_ccpvdz_PAR_HEA_v4_tapered__sha256_985901ca28fa7f97

Schema version4.0.0

Created (UTC)2026-09-07T11:05:42.346415+00:00

SHA-256 hash985901ca28fa7f97e38e5254c5e1a92a09d8080270898cb4befcb16a72ec0de2

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 parity \

--ansatz-type hea \

--reps 2 \

--multistart 3 \

--max-iter 500 \

--out-dir releases/v4/db

View raw JSON on GitHub