Abstract A superstructure of TiS 1.62 is determined by 100 kV high-resolution electron microscopy, in which the arrangement of metal vacancies is obtained from structure images. The crystal has monoclinic symmetry (pseudo-hexagonal) with lattice parameters a = 11.9, b = 6.85, c = 11.5Å, β = 90°. The space group is considered as F2 m . Metal vacancies are confined to every second metal layer and ordered within the partly filled metal layer, resulting in formation of a (2 H) 22 C type of superstructure. The ordered metal vacancy layers are arranged in 2 C-type stacking sequence along the c axis, while sulfur atoms are arranged in 2 H-type stacking sequence along the c axis.