The quantum mechanical description of normal valent and multivalent iodine in the polyoxides of the type IOnX, X=H, CH3, n = 1, 2, 3

The quantum mechanical investigation of normal valent and multivalent iodine in the polyoxides of the type IOnX, X=H, CH3, n = 1, 2, 3 is carried out in two series of computations using the MP2 methodology for the optimization procedure. The 6-311G basis set was used in the first series for all atoms involved. The same basis set was also employed in the second series for all atoms except iodine. Iodine was treated using the LANL2DZ ECP procedure, augmented with additional polarization functions. Refinement of the energetics was accomplished by performing single-point CCSD(T) calculations. The results emphasize the considerable improvement achieved in the quantum description of normal valent and multivalent I when extra polarization functions and relativistic corrections are taken into account.