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Qiskit Fermions
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.. warning::
   This package is under active development!
   If you have feedback, please `open an issue <https://github.com/Qiskit/qiskit-fermions/issues/new/choose>`_.

This package extends Qiskit with tools for working on fermionic systems.
It follows a similar design philosophy as Qiskit itself:

- the core functionality is written in Rust
- first-party language bindings are provided for both, Python and C
- the APIs are designed to "feel" similar to Qiskit

The scope of this package includes the following functionality:

- several operator data structures
- a framework to develop operator conversion methods
- a library of common operator converters
- a framework to develop quantum circuit synthesis methods
- a library of common quantum circuit synthesizers


Documentation
-------------

All documentation is available `here <https://qiskit.github.io/qiskit-fermions/>`_.


Installation
------------

Please refer to the `installation instructions <install.rst>`_.


Deprecation Policy
------------------

We follow `semantic versioning <https://semver.org/>`_ and are guided by the principles in
`Qiskit's deprecation policy <https://github.com/Qiskit/qiskit/blob/main/DEPRECATION.md>`_.
We may occasionally make breaking changes in order to improve the user experience.
When possible, we will keep old interfaces and mark them as deprecated, as long as they can co-exist with the
new ones.
Each substantial improvement, breaking change, or deprecation will be documented in the
`release notes <https://qiskit.github.io/qiskit-fermions/release-notes.html>`_.


Contributing
------------

The source code is available `on GitHub <https://github.com/Qiskit/qiskit-fermions>`_.

The developer guide is located at `CONTRIBUTING.md <https://github.com/Qiskit/qiskit-fermions/blob/main/CONTRIBUTING.md>`_
in the root of this project's repository.
By participating, you are expected to uphold Qiskit's `code of conduct <https://github.com/Qiskit/qiskit/blob/main/CODE_OF_CONDUCT.md>`_.

We use `GitHub issues <https://github.com/Qiskit/qiskit-fermions/issues/new/choose>`_ for tracking requests and bugs.


License
-------

`Apache License 2.0 <https://github.com/Qiskit/qiskit-fermions/blob/main/LICENSE.txt>`_


.. toctree::
  :hidden:

   Documentation Home <self>
   Installation Instructions <install>
   Tutorials <tutorials/index>
   Python API Reference <pydoc/index>
   C API Reference <cdoc/index>
   GitHub <https://github.com/Qiskit/qiskit-fermions>
   Release Notes <release-notes>