RC Oscillator for high frequency not working
There are other things wrong with the design, but here is a very simple analysis.  The LM7321 has a Gain-Bandwidth Product (GBW) of 20 MHz.  Your circuit has a primary frequency of 4 MHz.  At that frequency, the opamp has a gain of 5 and you need a gain of 29.  The opamp will not work in this application.