X-ray Debye temperature for hexagonal crystals

With the Debye continuum model an analytical expression is derived for the X-ray Debye temperature (θ_M) of a hexagonal crystal in terms of the elastic constants and this expression is used to calculate θ_M for hexagonal crystals of 41 elements and compounds. Calculated results by numerical integration are also presented for the X-ray Debye temperature perpendicular to the hexad axis, θ_⊥, and that parallel to it, θ_||. The calculated results are compared with experimental values, wherever data are available. A correction factor for the effect of dispersion is determined from the experimental data.