Update of the anharmonic force field parameters of the ozone molecule

A new set of spectroscopic constants of the O-16(3) molecule (omega(i), x(ij), y(ijk), gamma(DD), alpha(i)(x), beta(ij)(x),...), which determine vibrational dependence of band centres and rotational parameters, is derived from recent accurate analysis of high-resolution experimental ro-vibrational spectra through the theoretical approach based on secon&order perturbation expansions in normal coordinates accounting for Darling-Dennison resonance interactions. These values are used to update empirical values of anharmonic coefficients (k(ijl), k(ijlm)) of the potential function expansion in normal coordinates. Quadratic f(rr), f(ralpha), f(rr'), f(alphaalpha) as well as cubic f(rst) and quartic f(rstl) force constants in internal (bond lengths, bond angle) coordinates are also derived. A detailed discussion is devoted to the accuracy of parameter determination for each of four steps of calculations. It is emphasised that the conventional method based on the inversion of formulae of the perturbation theory gives the largest uncertainties at the last step of calculations: the determination of the anharmonic force field in internal coordinates. (C) 2002 Elsevier Science B.V. All rights reserved.