Thanks for the feedback. I'd like to think packing is generally crucial in biology for reasons of conserving space efficiently and enabling effective diffusion etc. alone. I suspect this is a somewhat unexplored criterion for protein function, and I hope the efficiency of packing of two proteins can be related if they interact or not. I'm unfamiliar with Rosetta, I think because I'm more familiar with the NLP approaches. I'll be sure to look into them.