Anharmonic coefficients in high symmetry directions for the diamond structure

Abstract

In this work, the cubic anharmonic coefficients are computed analytically in high symmetry directions considering central potential interactions up to fifth nearest neighbors for crystals with the diamond structure. It is found that certain channels of decay are forbidden. Furthermore particular relations between the different polarizations of the optical phonon for the cubic anharmonic coefficients are presented. Using these results, the validity of the so-called Peierls approximation is discussed.