Multielectron effects on the orientation dependence and photoelectron angular distributionof multiphoton ionization of CO2 in strong laser fields

摘要

We perform an ab initio study of multiphoton ionization (MPI) of carbon dioxide in intense linearly polar-ized laser pulses with arbitrary molecular orientation by means of a time-dependent density-functional theory(TDDFT) with proper long-range potential. We develop a time-dependent Voronoi-cell finite difference methodwith highly adaptive molecular grids for accurate solution of the TDDFT equations. Our results demonstratethat the orientation dependence of MPI is determined by multiple orbital contributions and that the electroncorrelation effects are significant. The maximum peak of MPI is predicted to be at 40° in good agreement withrecent experimental data. Photoelectron angular distribution reveals the delicate relation between the orienta-tion dependence and the molecular orbital symmetry.