Characterization of zero-point vibration in one-component crystals

We study the magnitude of zero-point vibrations in one-component crystals. For the crystals whose constituent atoms share the same bonding geometry, we prove the existence of a characteristic temperature, T₀, at which the magnitude of zero-point vibrations equals that of the excited vibrations. Within the Debye model T₀ is found to be 1/3 of the Debye temperature. The results are demonstrated in realistic systems.