def S(self, phase, T):
try:<EOL><INDENT>return self._phases[phase].S(T)<EOL><DEDENT>except KeyError:<EOL><INDENT>raise Exception("<STR_LIT>"<EOL>.format(phase, self.formula))<EOL><DEDENT>
Calculate the enthalpy 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] Entropy.