X-Seed 4: updates to a program for small-molecule supramolecular crystallography

X-Seed is a native Microsoft Windows program with three primary functions: (i) to serve as a graphical user interface to the SHELX suite of programs, (ii) to facilitate exploration of crystal packing and intermolecular interactions, and (iii) to generate high-quality molecular graphics artwork suitable for publication and presentation. Development of X-Seed Version 1.0 began in 1998, when point-and-click crystallographic software was still limited in scope and power. Considerable enhancements have been implemented within X-Seed over the past two decades. Of particular importance are support for the SHELX2019 programs (SHELXS, SHELXD, SHELXT and SHELXL) for structure solution and refinement, and MSRoll for rendering void spaces in crystal structures. The current version (i.e. Version 4) of X-Seed has a new interface designed to be more interactive and user friendly, and the software can be downloaded and used free of charge.