  We present PyFLOSIC, an open-source, general-purpose Python implementation of
the Fermi-L\"owdin orbital self-interaction correction (FLO-SIC), which is
based on the Python simulation of chemistry frame-work (PySCF) electronic
structure and quantum chemistry code. Thanks to PySCF, PyFLOSIC can be used
with any kind of Gaussian-type basis set, various kinds of radial and angular
quadrature grids, and all exchange-correlation functionals within the local
density approximation (LDA), generalized-gradient approximation (GGA), and
meta-GGA provided in the Libxc and XCFun libraries. A central aspect of FLO-SIC
are Fermi-orbital descriptors, which are used to estimate the self-interaction
correction. Importantly, they can be initialized automatically within PyFLOSIC
and optimized with an interface to the atomic simulation environment, a Python
library which provides a variety of powerful gradient-based algorithms for
geometry optimization. Although PyFLOSIC has already facilitated applications
of FLO-SIC to chemical studies, it offers an excellent starting point for
further developments in FLO-SIC approaches, thanks to its use of a high-level
programming language and pronounced modularity.
