Entry N2_ccpvdz_PAR_HEA_v4_casscf_tapered__sha256_1a06482cb89e4a67 | QEncode

VQE Gap

9.5040e-3 Ha

CASCI ref

-109.089958 Ha

Qubits (tapered)

CCSD(T) corr.

-3.248e-1 Ha

Molecule / Problem

NameN2

Basis setcc-pvdz

GeometryN 0.0 0.0 0.0; N 0.0 0.0 1.097

Charge0

Spin0

Active electrons6

Active orbitals6

Orbital optimizationCASSCF

Encoding / Circuit

Qubit mappingparity

Ansatz typehea

Ansatz reps (HEA)10

TaperingZ2 symmetry — 4 symmetries removed

Qubits (original)12

Qubits (tapered)8

Num parameters88

Circuit depth37

2Q gates70

Energy Results

HF energy-108.9542224390 Ha

MP2 energy-109.2646107945 Ha

CCSD energy-109.2671492732 Ha

CCSD(T) energy-109.2790637689 Ha

CASSCF energy-109.0899581524 Ha

CASCI ground state-109.0899581524 Ha

VQE best energy-109.0804541203 Ha

|VQE − CASCI| gap9.504032e-3 Ha

CCSD(T) correlation-3.248413e-1 Ha

Optimizer / Run Config

AlgorithmL-BFGS-B

Multistart runs5

Max iterations500

Total func evals371,523

Num parameters88

Backenddefault.qubit

Provenance / Reproducibility

Entry IDN2_ccpvdz_PAR_HEA_v4_casscf_tapered__sha256_1a06482cb89e4a67

Schema version4.0.0

Created (UTC)2026-07-15T14:05:26.155301+00:00

SHA-256 hash1a06482cb89e4a67518709b17ccbb99c9469a9131b4c1bd6f78aed476babdf04

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 N2 \

--mapping parity \

--ansatz-type hea \

--reps 10 \

--orbital-opt casscf \

--multistart 5 \

--max-iter 500 \

--out-dir releases/v4/db

View raw JSON on GitHub