WEASEL is our smart workflow driver. It fully automates quantum chemical workflows, and is used by experts and non specialists alike. WEASEL’s feature development is driven by the needs of our industry users, and often in close collaboration with them.

Democratizing quantum chemistry

WEASEL is our solution to make accurate quantum chemical simulations accessible to anyone, be it computational chemistry expert, data scientist, or experimentalist. It performs complex sequences of calculations, checks and collects their results, all in a black box fashion, allowing you to focus on the actual chemistry.

Smart workflows

WEASEL comes with a large set of predefined workflows, which automate various tasks, such as conformational searches, predicting reactivity or realistic spectra, computing chemical descriptors for data science applications, and more.

Expert know-how

Choosing the right methods, basis sets and other settings for quantum chemical calculations is often difficult, confusing, but simultaneously crucial for getting the right result for the right reason. We integrate this know-how into WEASEL’s standard workflows, which represent the best practices for each specific use case.

The settings are chosen based on recent literature, benchmark studies, and the expertise of our academic collaborators and advisory board, who share centuries of combined experience across many different fields of quantum chemistry.

Flexible & versatile

WEASEL uses best practice standard settings by default, but it is simple to customize the workflows to your specific needs and preferences. Furthermore, WEASEL supports various input and output formats, so it is easy to integrate into your company’s tool chain.


standard workflows

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Industry partners


  • Quality Management

    WEASEL automatically detects if an electronic structure is hard to converge, if initial structures are too far away from stationary points, and other problematic scenarios. It adapts the settings on-the-fly, in order to reliably deliver the expected results.

  • Efficient reporting

    The results are stored at various levels of verbosity, depending on your needs. Report files are created for archiving purposes. Additionally, WEASEL collects important data in standardized machine-readable summary files.

  • Multi-node capabilities

    WEASEL can run in parallel and across multiple nodes, using either the integrated or in-house OpenMPI libraries. Depending on type of the simulation and the size of the molecules, a single workflow might require hundreds to thousands of individual QM calculations. In such cases, hundreds of CPU cores can be used efficiently to speed up the computation.

  • Multiple file format support

    Various different chemical structure formats are supported, including: XYZ, MOL2, SDF, PDB, MAE, SMILES. These formats can be used to provide input structures and store output structures and data. Single- as well as multi-structure files can be handled.

  • Reactivity Prediction

    Various workflows for process chemistry applications are provided. For example, atomic or molecular reactivity descriptors of single molecular structures can be computed, but WEASEL also has efficient workflows to automatically predict reaction pathways, transition states, and lowest-energy conformers for small-to-medium sized molecular systems.

  • Spectrum Prediction

    Realistic infrared, Raman, NMR, UV/Vis, and circular dichroism spectra can be predicted, which take into account the conformational flexibility of the molecule. This is often essential when trying to reproduce or assign an experimental spectrum.

  • AI applications

    Data science projects can profit from various capabilities available in WEASEL. We provide workflows to generate molecular properties as well as atomic properties of all kinds, following scientific publications that have been suggested recently in AI-related projects.


The WEASEL tutorials and documentation are available to registered users.

Go to the tutorials

Get in touch

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