Single crystals of GeS2 are grown by two methods: crystallization from
a melt and chemical vapor transport. All crystals are found to have a
monoclinic structure with the unit-cell parameters a = 11.45 Angstrom
, b = 16.09 Angstrom, c = 6.7 Angstrom, and beta = 91 degrees. The ref
lection and transmission spectra are measured in the region of the abs
orption edge. The gap width is found to be equal to 3.2 eV. (C) 1998 A
merican Institute of Physics.