Entry H4_ccpvdz_PAR_HEA_v4_tapered__sha256_22ff67c44e248590 | QEncode

VQE Gap

5.6214e-3 Ha

CASCI ref

-2.186232 Ha

Qubits (tapered)

CCSD(T) corr.

-8.731e-2 Ha

Molecule / Problem

NameH4

Basis setcc-pvdz

GeometryH 0.0 0.0 0.0; H 0.0 0.0 1.0; H 0.0 0.0 2.0; H 0.0 0.0 3.0

Charge0

Spin0

Active electrons4

Active orbitals4

Orbital optimizationHF

Encoding / Circuit

Qubit mappingparity

Ansatz typehea

Ansatz reps (HEA)4

TaperingZ2 symmetry — 3 symmetries removed

Qubits (original)8

Qubits (tapered)5

Num parameters25

Circuit depth16

2Q gates16

Energy Results

HF energy-2.1664914658 Ha

MP2 energy-2.2312373418 Ha

CCSD energy-2.2529496914 Ha

CCSD(T) energy-2.2538030394 Ha

CASCI ground state-2.1862316746 Ha

VQE best energy-2.1806102812 Ha

|VQE − CASCI| gap5.621393e-3 Ha

CCSD(T) correlation-8.731157e-2 Ha

Optimizer / Run Config

AlgorithmCOBYLA

Multistart runs1

Max iterations500

Total func evals500

Num parameters25

Backenddefault.qubit

Provenance / Reproducibility

Entry IDH4_ccpvdz_PAR_HEA_v4_tapered__sha256_22ff67c44e248590

Schema version4.0.0

Created (UTC)2026-07-15T13:21:20.437584+00:00

SHA-256 hash22ff67c44e24859035b8fce7007b4d5b38afd2cfe893d3ee478c3f0313965a4d

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 H4 \

--mapping parity \

--ansatz-type hea \

--reps 4 \

--multistart 1 \

--max-iter 500 \

--out-dir releases/v4/db

View raw JSON on GitHub