  The thermal conductivity of several diamond-like materials is calculated from
a kinetic-collective model. From this approach, a thermal conductivity
expression is obtained that includes a transition from a kinetic (free) to a
collective (hydrodynamic) behavior of the phonon field. The expression contains
only three parameters. Once fitted to natural occurring silicon, the same
parameters for the other materials are directly calculated from theoretical
relations. The results are in good agreement with experimental data.
