SHTns is a high-performance Spherical Harmonic Transform library. It was designed for numerical simulation (fluid flows, mhd, etc.) in spherical geometries, but can be used for any kind of problem involving scalar or vector spherical harmonics. It is very fast, thanks to careful vectorization and runtime tuning. It supports multi-threaded transforms via OpenMP. It features scalar and vector transforms, synthesis and analysis, and flexible truncation and normalization. A Python interface is included.
V_Sim visualizes atomic structures such as crystals, grain boundaries, molecules, and so on It can work with files either in binary format or in plain text format. The rendering is done in pseudo-3D with colored spheres to represent the atoms. The user can interact through many functions to choose the view, the size of the atoms, their color, the background color, the type of fog, and more. Moreover, V_Sim allows you to export the view as images in GIF, PS, and other formats.