Phase Shift Oscillator not Oscillating
For some oscillators, it helps to "kick-start" to get them going in a simulation that doesn't model the noise that gets a real oscillator going. In this case, the kick-start is done by initializing node n005 to 0.01V (anything other than zero volts). Node 5 is at the right-hand end of C3:


This oscillator uses a virtual op-amp with open-loop gain of 100K. Since it has no power supply and is perfectly linear, oscillations grow exponentially...forever.

XU1 N001 0 N002 opamp Aol=100K GBW=10Meg
R1 N002 N001 180k
R2 0 N003 560
R3 0 N004 560
R4 0 N005 560
C1 N003 N002 .1µ
C2 N004 N003 .1µ
C3 N005 N004 .1µ
R5 N001 N005 5.6k
.IC V(n005)=.01
.tran 0 .1 0 .00001
.lib opamp.sub
.backanno
.end


Your oscillator also hasn't quite enough phase shift.