The different possible mechanisms of the temperature dependence of the tunnelling transition of an atomic particle in solids near absolute zero and the non-adiabatic effects are determined and considered. The general expression for the rate constant is obtained, taking into account the quantum properties of hydrogenous crystal. Comparison of the theoretical formula with experimental data [3] has permitted the leading mechanism, i.e. medium reorganization, of temperature dependence to be established. Good agreement has been achieved between theory and the discussed experimental data at reasonable values of the system parameters.