Basis set superposition error-counterpoise corrected potential energy surfaces. Application to hydrogen peroxide center dot center dot center dot X (X=F-, Cl-, Br-, Li+, Na+) complexes

Moller-Plesset (MP2) and Becke-3-Lee-Yang-Parr (B3LYP) calculations have be en used to compare the geometrical parameters, hydrogen-bonding properties, vibrational frequencies and relative energies for several X- and X+ hydrog en peroxide complexes. The geometries and interaction energies were correct ed for the basis set superposition error (BSSE) in all the complexes (1-5), using the full counterpoise method, yielding small BSSE values for the 6-3 11+G(3df,2p) basis set used. The interaction energies calculated ranged fro m 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 vibra tional frequencies. The minima on the BSSE-counterpoise corrected potential -energy surface (PES) have been determined as described by S. Simon, M. Dur an, and J. J. Dannenberg, and the results were compared with the uncorrecte d PES. (c) 1999 American Institute of Physics.