Molecules in intense laser fields: Enhanced ionization in one- and two-electron linear triatomic molecules

Numerical solutions of the time-dependent Schr\"odinger equation are presented to study the behavior of one and two electrons in symmetric and nonsymmetric linear molecules H₃²⁺ and H₃⁺. Enhanced ionization, as discovered earlier in diatomic molecules H₂⁺ and H₂ are shown to occur also in triatomic systems at critical internuclear separations that are determined by both field-induced barrier localization of the electron and charge resonance (CR) transitions. Two-electron effects manifest themselves through their influence on CR transition moments and electron collisions at large intensities.