ISSN:
1434-1948
Keywords:
Calculations
;
Bond theory
;
Electronic structure
;
Molecular dynamics
;
Kratzer
;
Morse
;
Potential energy curve
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
After decades of intensive research, the question remains whether or not a universal two- or three-parameter potential exists. For a large number of about 300 bonds, we now critically review the constraints for potentials and asymptotes, involved in three available scaling processes (Varshni, Calder-Ruedenberg, and Graves-Parr). We show that the covalent Sutherland parameter can never be a universal scaling factor. This implies that the usual constraint U(R) = -De at R = ∞ for potentials is only desirable and that the natural asymptote De is not even needed to explain the relations between the constants. We show that ionic potentials of generalized Kratzer-type (Varshni's Vth potential) and their ionic Coulomb-like asymptotes Ae2/Re (with A close to 1) behave as simple universal two-parameter potentials. For both αe and ωexe, this potential gives percentage deviations 2 to 3 times smaller than Morse's three parameter potential for hundreds of bonds. We also prove that the Graves-Parr scaling hypothesis is valid, despite these authors' own conclusion. We discuss various new relations between spectroscopic constants.Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2005/1999/99005_s.pdf or from the author.
Additional Material:
16 Ill.
Type of Medium:
Electronic Resource
