Multiwfn -

: Calculating and visualizing functions such as Electron Density , Electrostatic Potential (ESP) , Electron Localization Function (ELF) , and the Localized Orbital Locator (LOL) .

For decades, answering those "why" questions required deep expertise in arcane code or access to expensive, monolithic software suites. Then, in 2012, a quiet revolution began with a free, standalone program called . multiwfn

A quick search of the scientific literature reveals thousands of citations, spanning diverse fields: : Calculating and visualizing functions such as Electron