1975/06/24 by Hugh Christopher Longuet-Higgins · 2 citations
Chemistry · Physics and Astronomy · #Advanced Chemical Physics Studies #Molecular Spectroscopy and Structure #Quantum chaos and dynamical systems
paper · doi:10.1098/rspa.1975.0095
openalex publication_date 1975/06/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
Abstract It is proved that if the wave function of a given electronic state changes sign when transported adiabatically round a loop in nuclear configuration space, then the state must become degenerate with another one at some point within the loop. I t is further shown that this condition is satisfied by certain unsymmetrical triatomic systems, thereby disposing of a recent claim that the non-crossing rule for diatomic molecules applies also to polyatomic molecules.