Properties of the elements
The raw file (RData binary format, use R's load() function to open) contains the properties of the elements, scraped from periodictable.com.
The element-data.rda contains cleaned-up database of elemental properties, easily accessible for anyone with a working R install.
The blog post in the link below describes how to use this file (see the MWE section).
The csv files are ascii-formatted versions of the rda file's content.