differential inductor in momentum

i do not know how to set up the simulation for a differential inductor in momentum. i used differential ports, 1 port is normal other is reversed polarity and proper associations. the simulation works but i only get 1 port s-parameter results. i want 2port s-parameters to obtain L and Q. how do i do this? are these the correct equations to use:

Y=stoy(S)
L_diff=imag(1/Y12)/(2*pi*freq)
Q_diff=imag(1/Y12)/real(1/Y12)

thanks.