code: def Cp(self, phase, T):
          
  
          if phase not in self._phases:
              raise Exception("The phase '%s' was not found in compound '%s'." %
                              (phase, self.formula))
  
          return self._phases[phase].Cp(T)
docs: Calculate the heat capacity of a phase of the compound at a specified
          temperature.
  
          :param phase: A phase of the compound, e.g. 'S', 'L', 'G'.
          :param T: [K] temperature
  
          :returns: [J/mol/K] Heat capacity.