Analytical Potential Energy Function of the Ground State (X~3Σ_g~-) of O_2 Molecule

The reasonable dissoliation limits for O2 are determined based on the atomic and molecular reaction statics;the energy equilibrium geometry and harmonic frequency of the ground state X3Σ-g are calculated using the methods of CID,B3LYP,QCISD and QCISD(T) with the basis sets of D95(d),6-311G and 6-311G*.It is gained that the basis set 6-311G* is the most suitable for the energy calculation of O2 molecule.The whole potential curves for the ground state is scanned using QCISDC(T)/6-311G*,then fit to Murrell-Sorbie function and last spectroscopy constants(Be,αe,ωe,and ωeχe) are calculated,which are in good agreement with the experimental data.