.. Copyright 2023 NWChemEx-Project
..
.. Licensed under the Apache License, Version 2.0 (the "License");
.. you may not use this file except in compliance with the License.
.. You may obtain a copy of the License at
..
.. http://www.apache.org/licenses/LICENSE-2.0
..
.. Unless required by applicable law or agreed to in writing, software
.. distributed under the License is distributed on an "AS IS" BASIS,
.. WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
.. See the License for the specific language governing permissions and
.. limitations under the License.

################
ChemCache Design
################

This page details some of the decisions made in designing ChemCache.

**************************
Generation of Source Files
**************************

Most of the ChemCache library is autogenerated by the python scripts located in 
``utils/data_management``, using data either provided in the ``reference_data``
directory or downloaded from the internet by some of the ``data_management``
scripts. Of particular note, a limited selection of basis sets is provided in
the ``master`` branch. The script ``utils/data_management/scrape_bse.py`` can be
used to download additional basis sets from the 
`Basis Set Exchange <https://www.basissetexchange.org/>`__:

.. code-block:: console

    python -m venv data_venv
    source data_venv/bin/activate
    pip install -r requirements.txt
    python utils/data_management/scrape_bse.py /reference_data/basis_sets

Once the desired data for generating the source files as been
properly placed in ``reference_data`` (e.g. the set of basis sets), the
corresponding source files can be generated by the associated script:

.. code-block:: console

    source data_venv/bin/activate
    python utils/data_management/generate_basis.py /reference_data/basis_sets /src/chemcache/bases -r

Consult the ``data_management`` API documentation for more details on the usage 
of each of these scripts. The ``generated_data`` branch contains a version of 
ChemCache where a larger selection of basis sets (Dunning, Ahlrichs, and Pople 
types) have been included and the corresponding source files have been 
generated.