I am using make_fragments.pl with default options to generate fragment libraries and noticed that the 3mer and 9mer calculations are set to use different weighting schemes (see attached). Why is this? I haven't been able to find any documentation as to why you might want to use different weights for 3mers vs 9mers, or even why this particular weighting scheme is used in the first place (i.e. why are phi torsions weighted higher than psi torsions?). I'm curious because I would like to understand if these weights are appropriate for all fragment libraries or if they need to be optimized in some way for my specific protein. Thanks!