Reflectivity spectra of Hg1-xFexS (x < 0.04) and HgSe1-ySy (y < 0.5) m
ixed crystals were measured in the vacuum ultraviolet energy range fro
m 4 to 12 eV. Information about the electronic band structure of cubic
modification of HgS resulting from the above data is analyzed and dis
cussed.