Summary

I found the clips in the original design to be unnecessary, and required printing the oxygen atom half with the clips in a manner that left the surface finish of the atom a bit messy. I cut the clips off in Netfabb, and now two prints of this file can be used to create an oxygen atom rather than printing with two separate pieces with the clips and holes. This can also be printed with the flat side of the half-atom touching the build plate, and results in a cleaner overall finish to the surface of the atom. It requires a thin layer of superglue to hold together, but the final product with the hydrogen atoms attached is very stable and has a nice smooth surface.