Single crystals of the title compound up to a size of 5 mm were available from the elements via chemical transport reactions with TeBr 4 as transporting agent. The analysis by atomic emission spectrometry gave UTe 1.99(5) , i.e., stoichiometric composition. By single-crystal structure analysis we confirmed earlier results, according to which UTe 2 crystallizes orthorhombic in a unique structure type [space groupImmm,Z= 4 witha= 416.22(3) pm,b= 613.29(4) pm, andc= 1397.1(1) pm at ambient temperature]. The structure is built up by bicapped trigonal prisms of tellurium, connected via faces to fourfold capped biprisms. Because of the side-by-side arrangement pattern of the biprisms, linear chains of telluriums with distances far shorter than the nonbonding distance of Te 2− ions and slight alternation are observed. We report the results of an elaborate refinement of the crystal structure determined by X-ray diffraction (R w = 1.72%) and their behavior in the temperature range 10 K <T< 573 K using both powdered and single-crystalline samples to detect phase transitions as indications of structural or electronic changes.