Basis set superposition error - counterpoise corrected potential energy surfaces . Application to hydrogen peroxide ̄ X „ X 5 F

Mo/ ller–Plesset ~MP2! and Becke-3-Lee-Yang-Parr ~B3LYP! calculations have been used to compare the geometrical parameters, hydrogen-bonding properties, vibrational frequencies and relative energies for several X and X hydrogen peroxide complexes. The geometries and interaction energies were corrected for the basis set superposition error ~BSSE! in all the complexes ~1–5!, using the full counterpoise method, yielding small BSSE values for the 6-311 1G(3d f ,2p) basis set used. The interaction energies calculated ranged from medium to strong hydrogen-bonding systems ~1–3! and strong electrostatic interactions ~4 and 5!. The molecular interactions have been characterized using the atoms in molecules theory ~AIM!, and by the analysis of the vibrational frequencies. The minima on the BSSE-counterpoise corrected potential-energy surface ~PES! have been determined as described by S. Simón, M. Duran, and J. J. Dannenberg, and the results were compared with the uncorrected PES. © 1999 American Institute of Physics. @S0021-9606~99!30924-7#