Nonlinear interaction between dipole impurities in the strongly polarizable dielectrics

We calculated nonlinear corrections to the potential of interaction between impurity dipoles (e.g., ${\mathrm{Li}}^{+}$) in strongly polarizable dielectrics (e.g., ${\mathrm{KTaO}}_3$). The anharmonicity coefficient of the host lattice can be defined from normalizing conditions.