Abstract
THE Franck–Condon principle1 predicts that the vibrational quantum numbers v′, v″ of the strongest bands of a molecular spectrum lie on a family of open double-limbed quasi-parabolic curves in the v′v″ plane which are often roughly coaxial about v′ = v″. The curves are called the primary (outermost) and subsidiary (inner) Condon loci. The loci are indicated on a number of recently published Franck–Condon factor arrays2–4. The smaller the difference Δre between equilibrium internuclear separations r′ e and r″ e of the molecular potentials involved, the narrower are the loci and the closer is the apex of the primary locus to (0, 0). The greater Δre, the more open the loci, and the further the apex of the primary locus is from (0, 0) down the diagonal v′ = v″. The apices of the subsidiary loci are often spaced roughly two quantum numbers apart down the diagonal axis.
Similar content being viewed by others
Article PDF
References
Condon, E. U., Amer. J. Phys., 15, 365 (1947).
Nicholls, R. W., J. Res. Nat. Bur. Stand., 65, A, 451 (1961).
Nicholls, R. W., J. Res. Nat. Bur. Stand., 66, A, 227 (1962).
Nicholls, R. W., J. Quant. Spect. Rad. Transf., 2, 433 (1962).
Condon, E. U., Phys. Rev., 28, 1182 (1926).
Nicholls, R. W., Nature, 193, 966 (1962).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
NICHOLLS, R. Primary and Subsidiary Condon Loci of Molecular Spectra. Nature 199, 794 (1963). https://doi.org/10.1038/199794a0
Issue Date:
DOI: https://doi.org/10.1038/199794a0
This article is cited by
-
Geometry of Condon Loci of Molecular Spectra
Nature (1967)
-
Interpolation of Franck–Condon Factors
Nature (1964)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.