code: def get_compound_mass(self, compound):
          
  
          if compound in self.material.compounds:
              return self._compound_masses[
                  self.material.get_compound_index(compound)]
          else:
              return 0.0
docs: Determine the mass of the specified compound in the package.
  
          :param compound: Formula and phase of a compound, e.g. "Fe2O3[S1]".
  
          :returns: Mass. [kg]