Zero-range potential model for the description of atomic and molecular systems in a laser field

The method of zero-range potential is used to model negative atomic and quasimolecular ions in a circularly polarized laser field. The range of the laser-field parameters is extended in comparison with the previous calculations of the complex quasienergies of an atomic particle. A closed-form expression that defines the adiabatic electronic complex quasienergies of a two-state quasimolecular system is derived and solved numerically. Both laser-induced widths and shifts of the terms are discussed for a wide region of the laser-field parameters and internuclear distances, using H₂^- and OH^- ions as examples. The effect of suppression of the ionization rate of the excited state of a negative quasimolecular ion at small internuclear distances due to the presence of a laser field, as well as deepening of the ground-term potential well, was found.