Analytical potentials for triatomic molecules from spectroscopic data

A method already described to construct analytical potentials for triatomic molecules from spectroscopic data has been modified to cover several minima on the potential surface. A potential function for O3 has been obtained which satisfies the permutation symmetry of the molecule. It reproduces the harmonic force constants, equilibrium bond lengths and dissociation energy of the molecule and satisfies the criterion that there is no significant barrier to dissociation. The potential gives an optimum D3h configuration 2·76 eV above the true minimum (R = 1·28 Å) and there is a transition state for internal isomerization in C2ν configurations which is 0·30 eV below the dissociation limit.