The capacitive voltage -divider network, that's built up of C1 and C2, is effectively shunted over the crystal XTAL1 and capabilities because the responses network that causes the circuit to oscillate. The inverter delivers 180o of section change as well as crystal capacitor community the extra 180o demanded for oscillation. https://andyidaxu.diowebhost.com/89945236/a-secret-weapon-for-timing-components-for-consumer-electronics