Tutorial on Fitting of Potential Energy Surfaces

Abstract

In this paper we present a tutorial on fitting of potential energy surfaces that was given at the I European Computational Chemistry School on Molecular and Reaction Dynamics. The tutorial consists in four exercises that involve the use of a computer running under UNIX operating system, programs and subroutines for assembling and analyzing potential energy surfaces, numerical methods for fitting and graphical tools for the visualization of results. This paper explains the background of the exercises and guides the reader to the succesful completion of the exercises.The first exercise is devoted to fitting of potential energy surfaces (PES) by inter-polation methods. Thesecond exercise explains the useof the LEPS function to fit potential energy surfaces. In the third exercise the many-body expansion method is three-dimensional PES fora non-symmetric three-atom reaction. The applied tofita last exercise illustrates the useof bond order coordinatesto represent and develop potential energy functions. It also explains theconcept of many-process expansion.KeywordsPotential Energy SurfaceBond OrderDiatomic MoleculeInternuclear DistanceMorse PotentialThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.