  Much progress has been made over a long period, spanning more than a century,
in understanding the atomic arrangement on various length scales of
noncrystalline chalcogens and their transitions upon certain external stimuli.
However, it is broadly admitted that there are still several unsettled issues
that call for proper rationalization. The current review presents an assessment
of Raman scattering studies of noncrystalline phases of elemental chalcogens
and their mixtures. First, a few remarks on the analysis of Raman data, related
to polarization details and spectra reduction are presented. The effect of
temperature, pressure and irradiation on the structure of chalcogens is
reviewed in detail. As only selenium can form a stable glass at ambient
conditions, the interest on sulfur and tellurium has been placed in the melt
and the amorphous phase, respectively, whereas reference is also made to the
sporadic structural studies of glassy sulfur at low temperatures. It is shown
how Raman scattering can be exploited to explore unique phenomena emerging in
the liquid state of sulfur, offering valuable information on the details of
lambda transition including various thermodynamic related properties. The
subtle nature of this transition in selenium is also discussed. Tellurium is
not only impossible to be prepared in the bulk glassy state, but also forms a
very liable to crystallization amorphous film. Therefore, the emphasis is
placed on light induced nanostructuring and effects related to photo
amorphization and photo oxidation.
