<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def remove_oxidation_states(self):
 """ Removes oxidation states from a structure. """

        for site in self.sites:
            new_sp = collections.defaultdict(float)
            for el, occu in site.species.items():
                sym = el.symbol
                new_sp[Element(sym)] += occu
            site.species = new_sp