The origin of molecular distortions: a proposed experimental test

Bersuker and co-workers [Vibronic Interactions in Molecules and Crystals (Springer-Verlag, Berlin, 1989); Chem. Rev. 101, 1067 (2001); The Jahn-Teller Effect (Cambridge University Press, Cambridge, England, 2005); J. Chem. Phys. 124, 044321 (2006)] showed that the source of distortions from high symmetry configurations in molecules is vibrational-electronic (vibronic). It is here suggested that if one induces transitions by two consecutive operations (vibrational and electronic) performed in a given and in the reverse order, then the vibronic scenario gives different probabilities for the two orders, while an alternative scenario gives the same probability. The entanglement measure of the vibronic description is noted, and the broader aspect of the suggestion for experimentally testing state entanglements is discussed.