Characterization of 1T-TiSe2 surface by means of STM and XPD experiments and model calculations

► Surface structure 1T-TiSe2 has been characterized by means of STM and XPD methods. ► The TiSe2 structure was reconstructed from photoelectron holograms both Ti and Se. ► The 1T-TiSe2 surface structure does have 1T-polytype with distortion. ► The Van-der-Waals gap between two topmost slabs Se-Ti-Se is expanded. ► Lattice parameter a0 of TiSe2 structure is expanded up to 3.83 Å.