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