Hi Don,

From what I have read, the random congruent sphere packing is not a trivial problem.

http://neams.rpi.edu/jiw2/papers/2013_04_JCP_QDM.pdf

A google search of "Ho-Kei Chan" shows several papers, but they involve containers which are skinny cylinders.

A google search of "Mhand Hifi" yields several papers, with actual Algorithm code.

- Brian