A POTENTIAL-ENERGY SURFACE FOR THE ELECTRONIC GROUND-STATE OF N2O

A potential energy surface for the electronic ground state of N2O is o ptimized using a variational procedure with an exact vibrational Hamil tonian. In the optimization, the ab initio force field of Martin, Tayl or and Lee is taken as a starting point, and the observed vibrational band origins up to 15000 cm(-1) reported by Campargue and co-workers a re involved. The RMS error of this fitting to the 60 observed Sigma st ate vibrational energy levels is 0.34 cm(-1). The rovibrational energy levels for the Sigma and Pi vibrational states are calculated to test the refined potential.