COMPUTATIONAL STUDIES OF ATMOSPHERIC CHEMISTRY SPECIES .7. AN AB-INITIO STUDY OF THE N2...O2 HETERODIMER

The singlet and triplet potential energy surfaces for the N2...O2 hete rodimer have been investigated at the Hartree-Fock level of theory emp loying the 4-31 G and 6-31 + G basis sets. Four stationary points exh ibiting linear, T-shaped and parallel symmetric configurations have be en located and characterized according to the eigenvalues of the Hessi an matrix. Electron correlation effects, which play a fundamental role for weakly bound complexes, have been accounted for at the Moller-Ple sset second-order perturbation theory (MP2) level with the 6-31 + G b asis set. The triplet N2...O2 heterodimers are predicted to be stable bound systems, with the singlet complexes being unstable with respect to the isolated monomer subunits.