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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def site_symbols(self):
 """ Sequence of symbols associated with the Xdatcar. Similar to 6th line in vasp 5+ Xdatcar. """

        syms = [site.specie.symbol for site in self.structures[0]]
        return [a[0] for a in itertools.groupby(syms)]