Our implementation of approximate E min is available as an open-source software library. The library uses QCEngine to interface with a large suite quantum chemistry codes, Parsl to run computations in parallel, and Surge to generate isomers of molecules. Our recommended method for computing E min -xTB energies of the MMFF94 geometry of every isomer in PubChem -requires less than 2 minutes on a modern desktop computer for molecules up to 20 non-hydrogen atoms.