AbstractUsing Raman spectroscopy we have studied some effects of the 4felectron–phonon (magnetoelastic) coupling in CecNd1–cF3(0 ≤c≤1). This coupling manifests itself in the splitting of some twofold degenerate phonons in a magnetic field, accompanied by a reduction in linewidth, and in a zero‐field shift of phonon frequencies all depending onc. We have also studied the low lying (electronic) crystal field states of Nd3+(4I9/2) in NdF3and determined the eigenfunctions which have been used for a theoretical interpretation of the magnetoelastic effect