Entry H2CO_ccpvdz_JW_ADAPT_v4_tapered__sha256_09d774c657fca512 | QEncode

Molecule / Problem

NameH2CO

Basis setcc-pvdz

GeometryC 0.0 0.0 0.0; O 0.0 0.0 1.208; H 0.0 0.924 -0.540; H 0.0 -0.924 -0.540

Charge0

Spin0

Active electrons4

Active orbitals4

Orbital optimizationHF

Encoding / Circuit

Qubit mappingjordan-wigner

Ansatz typeadapt

Ansatz reps (HEA)1

TaperingZ2 symmetry — 4 symmetries removed

Qubits (original)8

Qubits (tapered)4

Num parameters1

Circuit depth20

2Q gates14

Non-Clifford gates8

T gates (FT estimate)96 (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-113.8747112406 Ha

MP2 energy-114.1946220638 Ha

CCSD energy-114.2099655671 Ha

CCSD(T) energy-114.2197587075 Ha

CASCI ground state-113.8969529437 Ha

VQE best energy-113.8958289967 Ha

|VQE − CASCI| gap1.123947e-3 Ha

CCSD(T) correlation-3.450475e-1 Ha

Optimizer / Run Config

AlgorithmADAPT-VQE (COBYLA inner)

Multistart runs1

Max iterations500

Total func evals19

Num parameters1

Backenddefault.qubit

Provenance / Reproducibility

Entry IDH2CO_ccpvdz_JW_ADAPT_v4_tapered__sha256_09d774c657fca512

Schema version4.0.0

Created (UTC)2026-07-16T09:35:23.779877+00:00

SHA-256 hash09d774c657fca5124cf682514ffcdb67cb9209d53c90de581c7d0e40c859277d

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 H2CO \

--mapping jordan_wigner \

--ansatz-type adapt \

--reps 1 \

--multistart 1 \

--max-iter 500 \

--out-dir releases/v4/db

View raw JSON on GitHub