Molecular dynamics of methanol cation (CH_3OH~+) in strong fields: Comparison of 800 μm and 7 μm laser fields

摘要

Fragmentation and isomerization of methanol cation by short, intense laser pulses were studied by ab initio classical trajectory simulations using CAM-B3LYP/6-31G(d,p) calculations. Compared to random orientation, CH_3OH~+ with the C—O bond aligned with the laser polarization gained nearly twice as much energy from the laser field, in accordance with the higher vibrational intensities in the mid-IR range for aligned CH_3OH~+. The energy gained by CH_3OH~+ from 7 μm and 800nm laser pulses with intensities of 0.88 x 10~(14) and 1.7 x 10~(14) W/cm~2 is proportional to the intensity and the wavelength squared of the laser field.