Knowledge Bank

Molecular spectroscopists sometimes overlook the inherent ambibuity in inverting from bound state energy level data to diatomic vibrational potentials V. This non-uniqueness is here illustrated by calculating RKR f-integrals for a series of P""{o}schl-Teller potentials all with identical vibrational levels. The f-inegrals calculated by the usual first-order WBK procedure are in error for all P""{o}oshal-Teller V’s except the limiting case - the Morse V. It is further pointed out that rotational data cannot correct for errors introduced in inverting vibrational data.