abstract:The Debye frequency of a crystal is a theoretical maximum frequency of vibration for the atoms that make up the crystal It was proposed by Peter Debye] as part of the [[Debye model. It is generally not the same as the actual maximum oscillation frequency for the crystal, due to approximations in the model, however it is still a useful quantity It plays a role in the computation of the specific heat capacity] of solids and in theoretical estimates of rates of [[diffusion.