In a magnetic field anions are known to possess, within the approximation of infinite nuclear mass, an infinite manifold of bound states. This approximation, however, neglects effects due to the coupling of the anionic center-of-mass (CM) motion to the electronic motion. The latter coupling turns out to be crucial for the mere existence and properties of the field induced anions. Therefore it is important to develop a theoretical approach to study anions in the presence of a magnetic field including the motional CM effects. This has been done in for the case of weak to moderate magnetic field strengths. The key ingredients of the developed approach are canonical transformations of the original Hamiltonian, implementing the integrals of motion and reasonable adiabatic approximations. The main result is establishing a three-dimensional Hamiltonian that can be universally applied to atomic or molecular negative ions in a magnetic field by specifying the properties (e.g., mass and polarizability) of the underlying neutral counterparts. For the classical dynamics a reduction to an effective two-dimensional problem is possible. The results obtained can serve as a basis for future rigorous investigations of moving anions in fields.

Page created by Alexander Potekhin (palex.astro@mail.ioffe.ru) on January 14, 2002.