Catalog of candidate ions for trapped ion quantum computing.  The periodic table is shown with the hydrogenic ions highlighted with links to individual pages. Included on each page are energy diagrams for the outer electron for each ion, the relative transition strengths for hyperfine transitions (useful for locating cooling transitions), links to more information about the physical properties, isotope information, and research groups using the ions for various projects.  In addition, several two electron ion systems have applications for both quantum computing and optical time standards.