Notch filter Lt spice

This is what i am working on right now a 3rd order inverted filter. well i am trying to figure out the correct component values to have a 500Hz notch filter . while using f = 1 / 2*pi*R*C .
R=R1=R2. R3=.5*R
C=C5=C6 . C4=2*C

it is strange that the graph isn't giving me notch graph. Perhaps i did something wronge