Json-serializable dict representation of PeriodicSite.

        Args:
            verbosity (int): Verbosity level. Default of 0 only includes the
                matrix representation. Set to 1 for more details such as
                cartesian coordinates, etc.

def as_dict(self, verbosity=0):
        """
        Json-serializable dict representation of PeriodicSite.

        Args:
            verbosity (int): Verbosity level. Default of 0 only includes the
                matrix representation. Set to 1 for more details such as
                cartesian coordinates, etc.
        """
        species_list = []
        for spec, occu in self._species.items():
            d = spec.as_dict()
            del d["@module"]
            del d["@class"]
            d["occu"] = occu
            species_list.append(d)

        d = {"species": species_list,
             "abc": [float(c) for c in self._frac_coords],
             "lattice": self._lattice.as_dict(verbosity=verbosity),
             "@module": self.__class__.__module__,
             "@class": self.__class__.__name__}

        if verbosity > 0:
            d["xyz"] = [float(c) for c in self.coords]
            d["label"] = self.species_string

        d["properties"] = self.properties
        return d