  Antimony telluroiodide (SbTeI) is predicted to be a promising material in
many technological applications based on theoretical simulations, however the
bulk structure solution remains elusive. We consolidate SbTeI belonging to the
base-centered monoclinic lattice with a space group C 2/m by combining single
crystal X-ray diffraction and X-ray photoemission spectroscopy techniques. The
atomic arrangement of the reported crystal structure is remarkable with
one-dimensional double-chains forming two-dimensional blocks. In this
structure, the Sb$^{3+}$ ion is surrounded by Te$^{2-}$ and I$^-$, which is
distinguishable by an incomplete polyhedron resulting in the 5s$^2$ (Sb) lone
pair electrons in the valence band. Manipulation of this material with pressure
to induce novel structures and properties is highly anticipated.
