Developer and API Guide

While this documentation focuses on the usage of Xatu as a command-line tool, developers may also use it as a library to integrate excitonic calculations into other workflows.

The Xatu source code exposes key functionalities via a documented C++ API, intended for direct use in scientific software development.

API Documentation

  • Full API documentation is available and maintained using Doxygen

  • To generate the API documentation:

cd docs
doxygen docs.cfg

This will produce a browsable HTML documentation of the internal structure and classes.

Code Structure Overview

The API is organized in a namespace, and its usage typically follows:

  1. Create a System object using a system file or subclass it to define a custom Hamiltonian.

  2. Pass the system to an Exciton object, which is then configured and solved.

  3. Extract results from the Result object: eigenvalues, eigenvectors, and observables.

Example structure:

systemConfig.reset(new xatu::SystemConfiguration(systemfile))
xatu::ExcitonTB bulkExciton = xatu::ExcitonTB(*systemConfig, *excitonConfig);
...
[calls relevant methods]
...
auto results = bulkExciton.diagonalize(method, nstates);

auto eigvals = result.eigenvalues();
auto eigvecs = result.eigenvectors();

  • API header files are located under include/

  • Example usages are available in the main/ directory