X-ray structural analysis of the high-pressure phase III of tellurium

A structure of a high-pressure phase of tellurium (Te-III) has been re-examined by an x-ray diffraction method. This phase appears at a pressure between 7 and 27 GPa, where a second-order phase transition to Te-IV occurs. The newly obtained crystal lattice of Te-III at 8 GPa is monoclinic with a = 8.4682(14) Å, b = 4.7424(8) Å, c = 3.9595(7) Å, β = 88.112(11)°. The space group is C 2/ m , with six atoms in the unit cell, two in positions 2a at (0, 0, 0) and four in positions 4i at ( x , 0, z ) with x = 0.324(11), z = 0.675(3).