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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 calculate_pore_diameter(self):
 """ Return the intrinsic pore diameter. Returns ------- :class:`float` The intrinsic pore diameter. """

        self.pore_diameter, self.pore_closest_atom = pore_diameter(
            self.elements, self.coordinates)
        self.properties['pore_diameter'] = {
            'diameter': self.pore_diameter,
            'atom': int(self.pore_closest_atom),
        }
        return self.pore_diameter