Multipole corrections to the electronic terms of a highly excited molecule

The properties are investigated of the electronic terms of a molecule with one of its electrons highly excited. These terms have a form similar to the ground electronic term of the corresponding molecular ion (core), and are obtained in the zeroth approximation by a parallel downward shift equal to Ry/n₂ and independent of the internuclear distances (symbasis property). The main causes of the deviation from this property are discussed. The nonsymbatic corrections, necessitated by the multipole interaction of the Rydberg electron with the ion core, are discussed. The possibility of using the results to detect new exciplexes is indicated.Translated from Trudy Fizicheskogo Instituta im. P. N. Lebedeva, Vol. 120, pp. 107–119, 1980.