It represents a set of common, standardized data for chemoinformatics
in both XML and plain-text formats. This data is open for common use,
under the expectation that others will contribute to the repository,
either via tabulations of additional properties or revisions/comments
on existing data.

The concept is that via shared default data, reproducing computational
chemistry and chemoinformatics will become more reproducible :-).

Currently this encompasses:
* Elements directory
* element names and symbols
* atomic masses, covalent radii, van der Waals radii
* Pauling electronegativities
* electron affinity
* ionization potential
* default element colors for viewers
* Isotopes directory
* exact masses of most abundant isotopes
* isotopic masses and abundances
* spin
* kinds of decay, percentages and energy
* magnetic dipole moment
* halflife