Angle-Dependent Ionization of Hydrides AHn Calculated by Time-Dependent Configuration Interaction with an Absorbing Potential

The angle dependence of strong-field ionization was studied for a set of second period hydrides (BH3, CH4, NH3, H2O, and HF) and third period hydrides (AlH3, SiH4, PH3, H2S, and HCl). Time-dependent configuration interaction with a complex absorbing potential was used to model ionization by a seven cycle 800 nm cosine squared pulse. The ionization yields were calculated as a function of the laser polarization and plotted as three-dimensional surfaces. The general shapes of angular dependence can be understood in terms of ionization from the highest occupied orbitals. Variations in the shapes with laser intensity indicate that ionization occurs not just from the highest occupied orbitals, but also from lower-lying orbitals. These deductions are supported by variations in the population analysis with the intensity of the laser field and the direction of polarization.