New Polarizability property is giving Quantities error

[rwest]

This is running an example input file (the methylformate one, fwiw):

Traceback (most recent call last):
  File "rmg.py", line 136, in <module>
    cProfile.runctx(command, global_vars, local_vars, stats_file)
  File "/usr/local/Cellar/python/2.7.3/Frameworks/Python.framework/Versions/2.7/lib/python2.7/cProfile.py", line 49, in runctx
    prof = prof.runctx(statement, globals, locals)
  File "/usr/local/Cellar/python/2.7.3/Frameworks/Python.framework/Versions/2.7/lib/python2.7/cProfile.py", line 140, in runctx
    exec cmd in globals, locals
  File "<string>", line 1, in <module>
  File "/Users/rwest/Code/RMG-Py/rmgpy/rmg/main.py", line 317, in execute
    self.initialize(args)
  File "/Users/rwest/Code/RMG-Py/rmgpy/rmg/main.py", line 234, in initialize
    self.loadInput(args.file[0])
  File "/Users/rwest/Code/RMG-Py/rmgpy/rmg/main.py", line 160, in loadInput
    readInputFile(path, self)
  File "/Users/rwest/Code/RMG-Py/rmgpy/rmg/input.py", line 244, in readInputFile
    exec f in global_context, local_context
  File "/Users/rwest/Code/RMG-Py/examples/rmg/methylformate/input.py", line 15, in <module>
    structure=SMILES("COC=O"),
  File "/Users/rwest/Code/RMG-Py/rmgpy/rmg/input.py", line 85, in species
    spec, isNew = rmg.reactionModel.makeNewSpecies(structure, label=label, reactive=reactive)
  File "/Users/rwest/Code/RMG-Py/rmgpy/rmg/model.py", line 297, in makeNewSpecies
    spec = Species(index=self.speciesCounter+1, label=label, molecule=[molecule], reactive=reactive)
  File "/Users/rwest/Code/RMG-Py/rmgpy/rmg/model.py", line 62, in __init__
    rmgpy.species.Species.__init__(self, index, label, thermo, conformer, molecule, lennardJones, molecularWeight, energyTransferModel, reactive)
  File "species.py", line 102, in rmgpy.species.Species.__init__ (build/pyrex/rmgpy/species.c:2259)
  File "species.py", line 161, in rmgpy.species.Species.setPolarizability (build/pyrex/rmgpy/species.c:3414)
  File "quantity.py", line 558, in rmgpy.quantity.UnitType.__call__ (build/pyrex/rmgpy/quantity.c:10208)
rmgpy.quantity.QuantityError: Invalid units ''.