openwfn 0.11.0

Wavefunction analysis, made reproducible.

A unified post-processing toolkit for turning quantum-chemistry calculations into traceable, reproducible, review-ready results.

Get started · CLI reference · Validation · Citation

openWFN connects scientific analysis, automation, validation evidence, and research output through one typed calculation model. It works locally through the command line or Python, from individual calculations and high-throughput collections.

Analyze · Automate · Validate · Publish

• Analyze molecular structure, orbitals, electron density, atomic populations, electrostatic potential, vibrational modes/spectra, excited states, and derived properties.
• Automate with stable CLI commands, a typed Python API, structured results, resumable batches, and JSON/CSV exports.
• Validate using explicit capability status, parser provenance, transformations, numerical controls, and fixture-backed evidence.
• Publish durable reports, figures, cube files, structures, and batch manifests.

Stable release 0.11.0

openWFN 0.11.0 integrates native Hirshfeld analysis, vibrational spectroscopy, and method-general excited-state/UV–Vis post-processing into the public stable package. Install the exact release with python -m pip install "openwfn[interop,resources]==0.11.0". See the release notes.

Stable package status does not make every scientific analysis Validated. The machine-readable validation manifest remains the authoritative capability-status registry:

• ordinary Hirshfeld populations/charges are Validated only for the named H/C/N/O all-electron ten-case scope and fixed tolerances;
• vibrational spectroscopy remains Experimental pending independent external spectroscopy validation;
• excited-state and UV–Vis analyses remain Experimental pending named independent cross-program/method validation.

The release retains the versioned 11-molecule everyday-QC corpus and runs a 110-command bounded workflow/resource matrix against both the built wheel and the package downloaded back from public PyPI.

Hirshfeld population analysis

openwfn calculation.fchk population hirshfeld

Ordinary neutral-pro-atom Hirshfeld analysis reports closure diagnostics and does not renormalize final charges to hide numerical residuals. Unsupported elements, ECP/pseudopotential ambiguity, and ghost-center ambiguity fail explicitly rather than using guessed pro-atoms.

Vibrational spectroscopy

openwfn frequency.log vibrations
openwfn frequency.log spectra ir --fwhm 20 --points 2001 --export ir.csv
openwfn frequency.log spectra raman --export raman.svg

Gaussian Raman activities are preserved as source activities and are not silently converted to experimental Raman intensities. Imaginary frequencies remain signed in source data and are excluded from broadened physical curves with explicit warnings. See the vibrational spectroscopy method page.

Excited states and UV–Vis

openwfn excited.log excited states
openwfn excited.log excited state 1
openwfn excited.log excited dipoles
openwfn excited.log spectra uvvis --fwhm-ev 0.20 --export uvvis.svg

The typed excited-state layer supports the implemented Gaussian, ORCA, and Q-Chem source adapters while preserving source method detail and explicit amplitude conventions. UV–Vis broadening is performed in energy space and the wavelength-domain curve uses the energy-to-wavelength Jacobian rather than relabeling the same y-array. Missing oscillator strengths are not treated as zero; dark f=0 states remain valid source states. See Excited states and UV–Vis.

Install

openWFN supports Python 3.10–3.13.

Install the stable release:

python -m pip install --upgrade openwfn
openwfn --version

Install the exact release when reproducing research:

python -m pip install openwfn==0.11.0

First analysis

openwfn examples install ./openwfn-examples
openwfn ./openwfn-examples/water.fchk doctor
openwfn ./openwfn-examples/water.fchk summary
openwfn ./openwfn-examples/water.fchk orbitals frontier

The same install command also places the versioned 11-molecule release corpus in ./openwfn-examples/everyday-qc/ for reproducible workflow checks.

For your own calculation, replace the example path:

openwfn molecule.fchk summary

Run a collection of calculations with resumable, structured output:

openwfn batch ./calculations \
  --analyses summary,frontier \
  --output-dir ./results \
  --resume

Use JSON when another program will consume the result:

openwfn --format json --output summary.json molecule.fchk summary

Scientific correctness safeguards

openWFN uses source-faithful electronic metadata wherever Gaussian FCHK provides it. ECP and ghost centers use the file's effective nuclear charges instead of blindly substituting atomic numbers, and density validation prefers the source electron-count records. Population and density conservation failures return partial results with warnings rather than presenting inconsistent numbers as clean successes.

For unrestricted calculations, request the spin-complete frontier view with openwfn FILE orbitals frontier --spin all; batch workflows support the same spin selection. Post-HF files explicitly report when the available SCF density is being analyzed rather than implying that a correlated density was used.

The default density spacing of 0.15 bohr is an accuracy/performance tradeoff, not a universal convergence guarantee. Check the returned conservation status and converge spacing/padding for the system and property being reported.

Capability map

“Validated” is deliberately scoped. Review the validation evidence and limitations before research use.

Input support

Version 0.11.0 includes optional interoperability support and the release safety contracts established on the 0.10 line. See the 0.11.0 release notes. Install python -m pip install "openwfn[interop]==0.11.0" for additional formats. The optional reader is pinned to IOData 1.0.1 and has a 25-format ingestion matrix with capability discovery. Format ingestion does not imply that every file has orbitals, density, or an applicable analysis. The cross-format validation compares five water representations from one originating calculation; it is not broad independent scientific validation.

Gaussian formatted-checkpoint (.fchk) remains the preferred full-wavefunction path. Gaussian .chk is a proprietary binary format; openWFN calls Gaussian's separately installed formchk utility and does not decode it directly.

XYZ, MOL/SDF, and PDB inputs provide structure-only records. The optional backend also reads structure, periodic, grid, and integral-only formats; use openwfn FILE capabilities to check the actual data before analysis.

In openWFN 0.11.0, use --input-format FORMAT_ID when a filename is ambiguous (for example, a GAMESS .dat). A structure without a complete wavefunction gets a partial summary; it does not get inferred orbitals, density, or electron counts. Mixed batches can use --format-map and record unsupported files with reasons in the manifest. A batch exits nonzero if any input fails or is unsupported. See the batch guide for the exact contract.

openwfn calculation.chk formchk calculation.fchk
openwfn calculation.fchk convert --to sdf --output molecule.sdf
openwfn calculation.fchk density cube density.cube

Documentation

Output properties preview

Version 0.11.0 can extract source-reported properties from QC text output through the optional cclib reader:

python -m pip install "openwfn[outputs]==0.11.0"
python -m openwfn.cli --format json calculation.out properties

Python exposes the same result through openwfn.read_output(path). See the output properties preview for units, provenance, missing-data behavior and the current Experimental validation boundary.

• First analysis
• CLI workflows
• Complete CLI reference
• Python API
• Scientific methods
• Vibrational spectroscopy
• Excited states and UV–Vis
• Validation status
• Optional workbench
• Troubleshooting

Security and privacy

Computations are local, but input and generated artifacts can contain unpublished research. Never post private checkpoint files, credentials, personal filesystem paths, or license details in public issues. Read the security and data-privacy guide.

Development

python -m pip install -e ".[test,docs]"
python -m pytest
python -m ruff check .
python scripts/run_validation.py
python scripts/check_docs.py --root .
python -m mkdocs build --strict