Document Type
Article
Publication Date
Spring 5-13-2013
Abstract
Franck–Condon factors are investigated for sequences of free
main-group diatomic molecules. Theory-based Condon loci
(parabolas) and Morse-potential loci are plotted on Deslandres
tables to verify if they, indeed, follow the largest Franck–Condon
factors. Then, the inclination angles of the Condon loci
are determined. Thus, entire band systems are quantified by
one variable, the angle. For all available isoelectronic sequences,
this angle increases from a central minimum toward
magic-number molecular boundaries. The theory for the Condon
locus gives the angle in terms of the ratio of the upperstate
to the lower-state force constants. It is concluded that
the periodicity is caused due to the fact that this ratio
becomes larger as rare-gas molecules are approached, a trend
that probably points to the extreme cases of the rare-gas molecules
themselves. Thus, molecular periodicity echoes atomic
periodicity in that data plots have extrema at molecules with
magic-number atoms, yet it does not echo the details of
atomic periodicity in series between those molecules.
Recommended Citation
International Journal of Quantum Chemistry, 113, 2078-2089, 2013 (DOI10.1002/qua.24469)