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, CH3OH+ 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 CH3OH+. The energy gained by CH3OH+ from 7 mu m and 800 nm 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. (C) 2014 Elsevier B.V. All rights reserved.