It has been shown theoretically that nature does not allow stable atomic multiply charged negative ions in vacuo. Moreover, there is no experimental evidence for the existence of atomic multiply charged negative ions (AMCNI). However, in the last decade it has been shown, both theoretically and experimentally, that the character of atomic systems changes drastically in a radiation field. For example, whereas distribution of the ground-state wave function of an electron in a Coulombic potential is spherically symmetric around the nucleus, in a superintense high-frequency laser field this wave function is extremely distorted. In case of linear polarization, the wave function splits up into two non-overlapping parts, an effect also referred to as dichotomy of the electronic wave function. For circular polarization, the distortion of the wave function leads to toroidal shaping.

H.G. Muller , H.G. Muller , M.V. Fedorov

van Duijn, E., Gavrila, M., Muller, H. G., & Muller, H. G. (1996). Multiply charged negative ions of hydrogen induced by a superintense high-frequency laser field. In H. G. Muller, H. G. Muller, & M. V. Fedorov (Eds.), Super-Intense Laser-Atom Physics IV : Proceedings of the NATO Advanced Research Workshop on Super-Intense Laser-Atom Physics (SILAP IV), Moscow, Russia, August 5-9, 1995 (pp. 233–244).