iRASPA: GPU-accelerated visualization software for materials scientists

A new macOS software package, iRASPA, for visualisation and editing of materials is presented. iRASPA is a document-based app that manages multiple documents with each document containing a unique set of data that is stored in a file located either in the application sandbox or in iCloud drive. The latter allows collaboration on a shared document (on High Sierra). A document contains a gallery of projects that show off the main features, a CloudKit-based access to the CoRE MOF database (approximately 8000 structures), and local projects of the user. Each project contains a scene of one or more structures that can initially be read from CIF, PDB or XYZ-files, or made from scratch. Main features of iRASPA are: structure creation and editing, pictures and movies, ambient occlusion and high-dynamic range rendering, collage of structures, (transparent) adsorption surfaces, cell replicas and supercells, symmetry operations like space group and primitive cell detection, screening of structures using user-defined predicates, and GPU-computation of helium void fraction and surface areas in a matter of seconds. Leveraging the latest graphics technologies like Metal, iRASPA can render hundreds of thousands of atoms (including ambient occlusion) with stunning performance. The software is freely available from the Mac App Store.