Systematics of spectroscopic constants of homonuclear diatomic molecules

A study has been made of the spectroscopic constants of homonuclear diatomic molecules to examine the possible existence of a universal potential energy function. Universal three-parameter potential energy function is defined. A compilation has been made of the best available data for dimers. Plots of certain dimensionless variables are made which broadly show the trend of values. Detailed results are presented for αe, and ωexe for the Morse, Rydberg and Varshni potentials. It is concluded that it is not possible to find a universal three-parameter potential energy function for all dimers but it seems to be possible for certain sets of molecules. Possible errors in certain spectroscopic constants of some molecules are pointed out.