A symmetry analysis and a simple dangling bond model were presented for the VZn− in ZnGeP2, identifying a possible Jahn–Teller distortion mechanism which could naturally explain the localization of the defect wave-function on two of the nearest-neighbouring P atoms, as deduced for the electron nuclear double resonance experiments.

Jahn–Teller Distortion of the Zinc Vacancy in ZnGeP2. X.S.Jiang, W.R.L.Lambrecht: Chinese Physics Letters, 2008, 25, 1075-8