Strong thermoelastic and temperature waves in crystalline lattice

We analyze essentially nonlinear system of acoustical and optical vibrations of a complex crystalline lattice consisting of two sublattices. The theory generalizes the Karman–Born–Huang linear theory which prescribes acoustic and optical modes of deformations of the complex lattice. The nonlinear version of the Karman–Born–Huang theory is developed by introducing nonlinear interacting periodic forces between sublattices due to an internal transmitting symmetry in displacement of sublattices for one period and more. Correspondent coupled nonlinear dynamic equations admit large displacements of atoms up to loss of the structural stability and cardinal lattice rearrangement under action of an external force and thermal loads. Moreover, thermal flows interact with acoustic and optical waves, and unusual fast speed temperature waves take place.