Lightshow is a Python library for easily generating computational spectroscopy input files. If you use our code, please consider citing our manuscript in the Journal of Open Source Software and our multi-code benchmark paper, which provides the methods and default parameters used in Lightshow.

Often, it can be daunting to create comprehensive, well documented databases of materials structures and their x-ray absorption spectra. Lightshow solves this problem, allowing new users to choose sensible defaults for their calculations, while simultaneously exposing all functionality for experts.

Lightshow aims to provide a "one-stop-shop" for input file generation, and currently supports the following codes:

• FEFF
• VASP
• OCEAN
• EXCITING
• Xspectra

with more on the way! The software is intended to be user-friendly, extensively documented and tested, and extendable for those users who wish to add additional spectroscopy functionalities. There are also a few comprehensive tutorials to help you get started.

Tutorials

We offer a few tutorials to get you started (with more on the way!)

#	Tutorial	Description	Notebook
1	Basic usage	Pull structure data from Materials Project, write input files for all codes
2	Spectral broadening	Utilities for broadening spectra

Installation

To install Lightshow, simply use pip

pip install lightshow

Make sure you've set your Materials Project v2 API key as well! You can find some documentation on how to query data here and how to set up your new API key here.

export MP_API_KEY="your_Materials_Project_v2_API_key"

(or preferably, add MP_API_KEY to your bash profile).

More details can be found at our documentation.

Development installation

For developers: after cloning Lightshow locally, install pre-commit via

pip install pre-commit
pre-commit
pre-commit install

and check that the tests (below) work correctly (these can be run via pytest). After cloning, simply use

pytest lightshow/_tests

or with coverage

pytest -v --cov --cov-report xml lightshow/_tests

We use helper scripts to parse the pyproject.toml file and install only specific packages required for certain parts of development. For development, we recommend installing all dependencies:

bash scripts/install.sh       # Install Lightshow's core dependencies
bash scripts/install.sh test  # Install the test requirements only
bash scripts/install.sh doc   # Install requirements for building the docs

Contributing

We welcome any and all contributions by the community, including pull requests, bug reports, etc. Please see our contributing document for more details!

Adding new spectroscopy codes

Adding new spectroscopy codes requires one to inherit the _BaseParameters class from lightshow.parameters._base. The new Parameters(_BaseParameters) object should have a write() method, which must take a target directory as an argument, as well as any other keyword arguments require to write the input file (most notably, the Pymatgen structure, either a unit or super cell). The name property must also be defined (corresponding to the name of the calculation, e.g. "VASP"). Take a look at the examples in the lightshow.parameters module for more details!

Funding acknowledgement

This research is based upon work supported by the U.S. Department of Energy, Office of Science, Office Basic Energy Sciences, under Award Number FWP PS-030. This research used resources of the Center for Functional Nanomaterials (CFN), which is a U.S. Department of Energy Office of Science User Facility, at Brookhaven National Laboratory under Contract No. DE-SC0012704. This work received partial funding by the German Research Foundation (DFG) through the CRC 1404 (FONDA), Projektnummer 414984028, and the NFDI consortium FAIRmat – project 460197019. C.V. acknowledges support by the Department of Energy, Basic Energy Sciences, Materials Science and Engineering Division, through the Midwest Integrated Center for Computational Materials (MICCoM).

The Software resulted from work developed under a U.S. Government Contract No. DE-SC0012704 and are subject to the following terms: the U.S. Government is granted for itself and others acting on its behalf a paid-up, nonexclusive, irrevocable worldwide license in this computer software and data to reproduce, prepare derivative works, and perform publicly and display publicly.

THE SOFTWARE IS SUPPLIED "AS IS" WITHOUT WARRANTY OF ANY KIND. THE UNITED STATES, THE UNITED STATES DEPARTMENT OF ENERGY, AND THEIR EMPLOYEES: (1) DISCLAIM ANY WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE OR NON-INFRINGEMENT, (2) DO NOT ASSUME ANY LEGAL LIABILITY OR RESPONSIBILITY FOR THE ACCURACY, COMPLETENESS, OR USEFULNESS OF THE SOFTWARE, (3) DO NOT REPRESENT THAT USE OF THE SOFTWARE WOULD NOT INFRINGE PRIVATELY OWNED RIGHTS, (4) DO NOT WARRANT THAT THE SOFTWARE WILL FUNCTION UNINTERRUPTED, THAT IT IS ERROR-FREE OR THAT ANY ERRORS WILL BE CORRECTED.

IN NO EVENT SHALL THE UNITED STATES, THE UNITED STATES DEPARTMENT OF ENERGY, OR THEIR EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, SPECIAL OR PUNITIVE DAMAGES OF ANY KIND OR NATURE RESULTING FROM EXERCISE OF THIS LICENSE AGREEMENT OR THE USE OF THE SOFTWARE.