Background

PyDFT is a pure-Python package for performing DFT calculations, extending upon the functionality of PyQInt and leveraging a number of other packages such as PyLebedev and PyTessel for quadrature on the unit sphere and generation of isosurfaces, respectively.

Tip

More information on the inner workings of PyDFT can be obtained from the textbook “Elements of Electronic Structure Theory” (specifically chapter 4), which is freely available via this website.

Molecular decomposition

Solving the integrals involved in the electronic structure calculation is handled by means of numerical integration, also termed quadrature. The quadratures are solved by decomposing the molecule into so-called “fuzzy” cells as documented in the work of Becke.

Hartree potential

Electron-electron repulsion is handled by calculating the Hartree potential by means of solving Poisson’s equation. This equation is solved per fuzzy cell, as detailed in the seminal paper of Becke.

Exchange-correlation functions

PyDFT currently supports two exchange-correlation functions:

• LDA: Slater exchange + SVWN5 for the correlation

• PBE: The (standard) Perdew-Burke-Ernzerhof exchange-correlation functional