Abstract
A theory of the relative intensity of the various bands in a system of electronic bands is developed by an extension of an idea used by Franck in discussing the dissociation of molecules by light absorption. The theory predicts the existence of two especially favored values of the change in the vibrational quantum numbers, in accord with the empirical facts as discussed by Birge.
A means of calculating the intensity distribution from the known constants of the molecule is presented and shown to be in semi-quantitative agreement with the facts in the case of the rollowing band systems: SiN, AlO, CO (fourth positive group of carbon), I2 (absorption), O2 (Schumann-Runge system), CN (violet system), CO (first negative group of carbon), N2 (second positive group of nitrogen), and N2 (first negative group of nitrogen).
In the case of I2 there is a discrepancy, if Loomis’ assignment of n” values is used, which does not appear if Mecke’s original assignment is used. It is suggested that at least some of the lower levels postulated by Mecke are real but that absorption from them always results in dissociation of the molecule and so they are not represented in the quantized absorption spectrum.
A preliminary account of this paper was presented at the meeting of the Pacific Coast Section of the American Physical Society at Stanford University in March, 1926.
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References
Sommerfeld, Atombau und Spektrallinien. 4th ed., Chap. 5.
Chapter IV, Sec. 4, of National Research Council Report on Molecular Spectra (in press). The writer is indebted to Professor R. T. Birge for the opportunity to use the manuscript copy of this report.
Heisenberg, Zeits. f. Physik 33, 879 (1925);
Born and Jordan, Zeits. f. Physik 34, 858 (1925);
L. de Broglie, Ann. d. Physique 3, 22 (1925);
Schrödinger, Ann. der Physik 79, 459 (1926).
Sommerfeld, Atombau, 4th ed., Chap. 9.
The formulas are given by Born and Hückel, Phys. Zeits. 24, 1 (1925). The nomenclature used here is that of the Report on Molecular Spectra.
Franck, Trans. Faraday Society (1925).
Born, Vorlesungen über Atommechanik, pp. 39, 57.
Birge, Phys. Rev. 25, 240 (1925), Abstract No. 23, also Chap. IV, Sec. 4, Report on molecular spectra.
Mulliken, Phys. Rev. 26, 319 (1925); Jevons, Proc. Roy. Soc. 89A, 187 (1913–14).
Birge has made estimates from unpublished spectrograms taken by him at the University of Wisconsin. Also Eriksson and Hulthén, Zeits. f. Physik 34, 775 (1925).
Birge, Nature 117, 229 (1926);
Lowry, J.O.S.A. 8, 647 (1924).
The analysis is due to Mecke, Ann. d. Physik 71, 104 (1923), with Loomis’ revision of the quantum assignment. The values of B 0 8 and α are due to Loomis (Chapter VI, Report on Molecular Spectra), that of a”, however, having been previously given by
Kratzer and Sudholt, Zeits. f. Physik 33, 144 (1925).
As Loomis points out, the values of a are quite uncertain. For new observations on resonance spectra, see Dymond, Zeits. f. Physik, 34, 553 (1925).
Schumann, Smithsonian Contrib. 29, no. 1413 (1903);
Runge, Physica 1, 254 (1921);
Mulliken, Private communication to Professor Birge; Leifson, Astrophys. J. 63, 73 (1926);
Füchtbauer and Holm, Phys. Zeits. 26, 345 (1925); Report on Molecular Spectra, Chap. IV, Section 7.
Kayser’s Handbuch, v. 5, p. 190.
Johnson, Proc. Roy. Soc. 108A, 343 (1925);
Blackburn, Proc. Nat. Acad. 11, 28 (1925).
Merton and Pilley, Phil. Mag. 50, 195 (1925).
Lenz, Zeits. f. Phys. 25, 299 (1924).
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Condon, E.U. (1991). A Theory of Intensity Distribution in Band Systems. In: Barut, A.O., Odabasi, H., van der Merwe, A. (eds) Selected Scientific Papers of E.U. Condon. Springer, New York, NY. https://doi.org/10.1007/978-1-4613-9083-1_1
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