Several theoretical and experimental studies (DFT calculations and neutron scattering experiments) have been performed recently to understand the phonon modes that are coupled most strongly with ionic conductivity and assess the role of anharmonicity. It has been ascertained that the anharmonicity inherent in the phonon vibrational modes of the host lattice exhibits substantial coupling with cationic diffusion. This phenomenon has been notably observed in AgI . The recognized strong coupling between mobile ions and the host lattice holds pivotal importance for the diffusion process. Furthermore, investigations extended to materials like AgCrSe 2 , CuCrSe 2 , Li 7 P 3 S 11 , Li 10 GeP 2 S 12 , β-Li 3 PS 4 , Li 3 YBr 6 , and Li 3 ErCl 6 have revealed analogous coupling phenomena (Niedziela et al., ; Xu et al., ).