py4DSTEM is a free, open source, python-based data analysis package for the emerging field of fourdimensional scanning transmission electron microscopy (4D-STEM). In 4D-STEM, the electron beam is rastered across a sample and a diffraction pattern is collected at each scan position, yielding highly information-rich datasets which can be used to virtually recreate images that map sample orientation, local lattice parameters, strain, and short/medium range ordering, or to reconstruct the electrostatic potential itself [1]. These datasets can easily reach tens or even hundreds of GB in size, and almost always require significant computational processing to extract useful results. The aim of py4DSTEM is to make 4DSTEM data analysis easy and accessible for everyone [2]. READ MORE