Abstract
Results of calculations of vibrational densities of states and of infrared and Raman spectra for relatively large model structures representing elemental amorphous semiconductors are presented and discussed. Models for four-coordinated (germanium-like), three-coordinated (arsenic-like), and two-coordinated (selenium-like) materials are included and, where possible, we compared the results with experiment and discuss the limits within which the simple models can be expected to reproduce the behaviours of real materials.