Substructure Name Selection (#42)
Substructure Name Selection (#42)

Since the argparse argument was already present without any use, I added
in logic to gather data based off of the users preference with the default
being 'OPT'. This is useful if you want to gather data from a particular
substructure that you are not parameterizing.
ericchansen/q2mm,Q2MM/q2mm,ericchansen/q2mm,Q2MM/q2mm