The crystal structure of covellite CuS under high pressure Up to 33 kbar

The crystal structure of covellite has been studied under pressure up to 33 kbar based on single-crystal diffraction intensities collected with a four-circle diffractometer. The contraction of the unit cell takes place in such a way that the axial ratio e/a is kept nearIy constant, the cell volume at 1 bar being reduced by about 5% at 33 kbar. With the contraction of the Cu S bonds the sulfur-sulfur bond of the S2 group shows a trend of lengthening in a way similar to the relation between S S and M S bonds in the compounds MS2 (M = Cu, Ni, Co, Fe) having the pyrite structure type.