The δ Point Interaction Two-Center System

Motivated by the behavior of molecules in strong magnetic fields, we study the quantum system consisting of a particle (electron) interacting with two fixed (nuclear) centers by delta-type point interactions. Spectral properties and resonances of this model as a function of the internuclear separation are investigated qualitatively and quantitatively. We prove analyticity, monotonicity, and other features, compare them with corresponding attributes of related Coulomb systems, and point out the consequences for molecules. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109:1430-1441, 2009