# Global fit of ab initio potential energy surfaces: II.2. Tetratomic systems A 2 B 2 and ABC 2

## Description

Abstract Global potential energy surfaces (GPES) for tetratomic molecular systems, containing at least one group of two identical nuclei, which fit ab initio data can be obtained preserving the accuracy of the ab initio points. The permutational symmetry of the potential, corresponding to the two identical nuclei, is treated analytically in this new version of the previous published program GFIT4C (Computer Physics Communications catalogue number: ADNB). The global fit obtained fulfills the stringent ... Title of program: GFIT4C-2 Catalogue Id: ADOV_v1_0 Nature of problem Given a set of ab initio points of a molecular system with N atoms, the problem is to obtain a golbal analytical (3N - 6)-dimensional representation of the corresponding adiabatic potential having all the symmetry properties of the system and satisfying the stringent criteria [1] needed in molecular dynamical calculations. In Part II.1 [4] of this series we have dealt with the tetratomic system class ABCD and six-dimensional (6D) representation (program GFIT4C). In the present Part II.2 we treat ... Versions of this program held in the CPC repository in Mendeley Data ADOV_v1_0; GFIT4C-2; 10.1016/S0010-4655(01)00289-2 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)