Figure 3
The atomic displacement of atoms for the \(\Gamma _1^+\) (A\(_{1g}\)) phonon mode symmetry. Calculated at12 for CePd2Al2. For clarity the displacement of each atom is 4 times enlarged. The labels #13 #18 #30 correspond to the notation used in Supplementary information, which labels the modes for a given \(\mathbf{q}\) with increasing energy. The red, blue and green colours correspond to Ce, Pd and Al ions, respectively. The open circles represents static atoms in the mode.
