Abstract. Vl+xSe 2 is trigonal, space group P3ml, with a = 3.356 (1), c = 6.104 (2)A. The structure was refined to R(F) = 0.022 for 1441 observed reflections. The structure (CdI 2 type) consists of selenium layers perpendicular to the c axis, defining two octahedral sites (000,00,}). Vanadium atoms V(1) fill 000 sites and the small amount x of vanadium atoms V(2) occupies 00~ sites.