Title The Dual Role of Halogen, Chalcogen, and Pnictogen Atoms as Lewis Acid and Base: Triangular XBr:SHX:PH2X Complexes (X 5 F, Cl, Br, CN, NC, OH, NH2, and OCH3) Type JournalPaper Keywords Not Registered! Abstract Not Registered! Researchers (Third Researcher), Mehdi D. Esrafili (Second Researcher), Mehdi D. Esrafili (First Researcher)