Comparison of empirical closed-form functions for fitting diatomic interaction potentials of ground state first- and second-row diatomics

摘要

Twenty-one empirical potentials, having simple functional forms and varying numbers of adjustable parameters, were fitted to experimental RKR data for the ground states of 14 first- and second-row diatomics. The goodness-of-fit was evaluated in each case using the statistical least-squares Z-test of Murrell and Sorbie, and functions with more parameters generally produced better fits (lower Z values), as expected. The dependence of the goodness-of-fit varied in a complicated way with the number of adjustable parameters; for a given number of parameters, some functions outperformed others, indicating that certain functional forms give rise to inherently better empirical potentials, at least for the limited set of diatomics selected here. (c) 2005 Elsevier B.V. All rights reserved.