def Pc_mixture(Pcs=None, zs=None, CASRNs=None, AvailableMethods=False, Method=None):  
def list_methods():<EOL><INDENT>methods = []<EOL>if none_and_length_check([Pcs]):<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>return mixing_simple(zs, Pcs)<EOL><DEDENT>elif Method == '<STR_LIT:None>':<EOL><INDENT>return None<EOL><DEDENT>else:<EOL><INDENT>raise Exception('<STR_LIT>')<EOL><DEDENT>
This function handles the retrival of a mixture's critical temperature.

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

    >>> Pc_mixture([2.2E7, 1.1E7], [0.3, 0.7])
    14300000.0