‘‘Clustering modes’’ in the vibrational spectra of ${\mathrm{Hg}}_{1\mathrm{-}\mathrm{x}}$${\mathrm{Cd}}_{\mathrm{x}}$Te alloys

The spectral densities of states for phonons in ${\mathrm{Hg}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Cd}}_{\mathrm{x}}$Te alloys are predicted using the recursion method and are compared with Raman scattering data. The ‘‘clustering mode’’ observed by Amirtharaj et al. is shown to be an ‘‘alloy mode’’ associated with vibrations of a Te atom bonded to one Cd atom and three Hg atoms. ${\mathrm{Hg}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Cd}}_{\mathrm{x}}$Te is shown to be a ‘‘two-mode’’ alloy vibrationally.