Nonperturbative time-dependent density functional theory (TDDFT) and time-dependent electron localization TDELF) study of the ionization of OCS and CS2 with ultrashort intense laser pulses - Orientational effects

作者：Penka Emmanuel Fowe^*; Bandrauk Andre Dieter

来源：Canadian Journal of Chemistry, 2012, 90(7): 616-624.

DOI：10.1139/V2012-039

• molecular ionization
• ionization potential
• electron localization function
• density functional theory

The nonlinear nonperturbative response of OCS and CS2 to ultrashort (few cycles) intense laser pulses was studied numerically by time-dependent density functional theory (TDDFT) methods to understand molecular ionization as a function of laser-molecule orientation. A time-dependent electron localization TDELF) was used to visualize the nonlinear nonperturbative electron transfer occurring during the laser pulse. It was found that, for intensities I %26gt; 3.5 x 10(14) W/cm(2), the inner shell Kohn-Sham (KS) molecular orbitals contribute significantly to the ionization, whereas for the intensity I %26lt; 3.5 x 10(14) W/cm(2), the highest occupied molecular orbital (HOMO) shows the dominant response to the field. In general, the ionization rate maxima correspond to the alignment of maximum KS orbital densities with the laser pulse polarization instead of orbital ionization potentials (IP). These findings are corroborated through analysis of the TDELF images, where the ionization occurs from the lone pair or bond regions of the corresponding molecules.

• 出版日期2012-7