Molecular Borromean Rings model

See this wikipedia article:
http://en.wikipedia.org/wiki/Molecular_Borromean_rings
Chemists took on the challenge of creating a compound with the structure of the famous Borromean rings, three rings linked together among which no two are linked. The compound depends on six zinc ions, represented by the balls in the photo, for its synthesis and stability.
The STL provided is scaled to fit glass marbles, 16mm in diameter. It can be scaled to fit other sized balls, for example the pinball v