PyFLOSIC: Python-based Fermi–Löwdin orbital self-interaction correction

• Published in: The Journal of chemical physics Vol. 153; no. 8; pp. 084104 - 84117
• Main Authors: Schwalbe, Sebastian, Fiedler, Lenz, Kraus, Jakob, Kortus, Jens, Trepte, Kai, Lehtola, Susi
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 28.08.2020
• Subjects: Algorithms; Approximation; Computer simulation; Electronic structure; High level languages; Mathematical analysis; Modularity; Optimization; Programming languages; Python; Quadratures; Quantum chemistry
• ISSN: 0021-9606; 1089-7690; 1089-7690
• DOI: 10.1063/5.0012519

We present pyflosic, an open-source, general-purpose python implementation of the Fermi–Löwdin orbital self-interaction correction (FLO-SIC), which is based on the python simulation of chemistry framework (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, generalized-gradient approximation (GGA), and meta-GGA provided in the libxc and xcfun libraries. A central aspect of FLO-SIC is the Fermi-orbital descriptors, which are used to estimate the self-interaction correction. Importantly, they can be initialized automatically within pyflosic; they can also be optimized within pyflosic with an interface to the atomic simulation environment, a python library that 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.