Oscillations of atomic nuclei in crystals are considered in this paper. It is shown that elastic nuclei oscillations relatively electron envelops (inherent, I-oscillations) and waves of such oscillations can exist in crystals at adiabatic condition. The types and energy quantums of I-oscillations for different atoms are determined. In this connection the adiabatic crystal model is offered. Each atom in the adiabatic model is submitted as I-oscillator whose stationary oscillatory terms are shown as deep energy levels in crystals. The I-oscillations can be created at the expense of recombination energy of electrons and holes on electron-vibrational centers in semiconductors. They interact among themselves, with phonons and electrons, they influence on physical properties of crystals and crystal structures. The I-oscillations representing oscillations of atomic nuclei relatively electron system in crystals or molecules are the important physical reality.