Hi, I need for my last term movie at School to model some kind of crystal structures (mainly bismuth crystals) , and see if it is possible to make it procedural.
Here are some links to references:

http://periodictable.com/Samples/083.14/s13.JPG [periodictable.com]
http://th05.deviantart.net/fs6/PRE/i/2005/069/c/4/Bismuth_Again_by_froggynaan.jpg [th05.deviantart.net]

I was thinking of trying to create a rough shape of the crystal, scatter points and then instanciate the cube which can be seen on top. From my test, it doesn't seem to work and get good result. Do you have any other ideas how I should approach this?

I might have found a way which could work for some cases, it's based on a curve which is then extratec and copied. Here is the file (made with 12.5 as my school doesn't have Houdini 13.0)