GLOBAL FIT OF AB-INITIO POTENTIAL-ENERGY SURFACES - I - TRIATOMIC SYSTEMS

Global potential energy surface (PES) for molecular systems which fit ab initio data can be obtained preserving the accuracy of the ab initi o points. The global fitting technique is based in a procedure for tri atomic systems including the functional form previously proposed by th e authors. The global fit obtained maintains all the symmetry properti es of the system including the permutational symmetry and fulfills the stringent criteria needed for molecular dynamical calculations. The p rogram writes out as output file a Fortran-77 program in a form such t hat the potential and its derivatives with respect to coordinates can be evaluated readily and accurately at arbitrary geometries. (C) 1998 Elsevier Science B.V.