AbstractRecent experimental results on the anisotropy of the Kronig Van Vleck one‐phonon spin‐lattice relaxation rates of self‐trapped hole centres in KBr, RbBr, and KI are used to obtain electron‐vibration interaction constants for even non‐totally symetric vibrations of VKcentres. A simple centre model, consisting of the X 2−molecule and two nearest cations with normal vibrations of β1g, β2g, and β3g symmetry, is used. A qualitative agreement with the experimental data on various cations and anions can be obtained when ion size corrections are taken into account in evaluating electron‐vibrati