Carbonyl sulphide under strong laser field: time-dependent density functional theory

The first 52 fs of a time evolution of the electron density in OCS after an interaction with an intense sub 10 fs laser pulse are studied using the time-dependent density functional theory. The nuclear motion in this linear trimer is simulated by the classical molecular dynamics method. Laser fields of intensity 10^{13} W/cm^2 and 10^{15} W/cm^2 are used. Details of the laser induced changes of the structure, as well as the ionization rate are sensitive to the applied field intensity and its polarization. It is found that under suitable conditions the OCS molecule bends soon after an interaction with a laser pulse. A deviation from the linear geometry of up to 23.6^\circ and charged ions of up to +3 are observed. The time evolution of electric dipole moments and the time-dependent electron localization function (ELF) are also studied.