def Hfus(T=<NUM_LIT>, P=<NUM_LIT>, MW=None, AvailableMethods=False, Method=None, CASRN='<STR_LIT>'):  
def list_methods():<EOL><INDENT>methods = []<EOL>if CASRN in CRCHfus_data.index:<EOL><INDENT>methods.append('<STR_LIT>')<EOL><DEDENT>methods.append('<STR_LIT:None>')<EOL>return methods<EOL><DEDENT>if AvailableMethods:<EOL><INDENT>return list_methods()<EOL><DEDENT>if not Method:<EOL><INDENT>Method = list_methods()[<NUM_LIT:0>]<EOL><DEDENT>if Method == '<STR_LIT>':<EOL><INDENT>_Hfus = CRCHfus_data.at[CASRN, '<STR_LIT>']<EOL><DEDENT>elif Method == '<STR_LIT:None>' or not MW:<EOL><INDENT>_Hfus = None<EOL><DEDENT>else:<EOL><INDENT>raise Exception('<STR_LIT>')<EOL><DEDENT>_Hfus = property_molar_to_mass(_Hfus, MW)<EOL>return _Hfus<EOL>
This function handles the calculation of a chemical's enthalpy of fusion.
    Generally this, is used by the chemical class, as all parameters are passed.
    Calling the function directly works okay.

    Enthalpy of fusion is a weak function of pressure, and its effects are
    neglected.

    This API is considered experimental, and is expected to be removed in a
    future release in favor of a more complete object-oriented interface.