3-DIMENSIONAL CARTESIAN FINITE-ELEMENT METHOD FOR THE TIME-DEPENDENT SCHRODINGER-EQUATION OF MOLECULES IN LASER FIELDS

A finite element (FE) method in three-dimensional Cartesian coordinates is described to solve the time dependent Schrödinger equation for H 2+, H2, and H3+ in the presence of time dependent electromagnetic fields. The ionization rates and harmonic generation spectra have been calculated for these molecules for field directions parallel or perpendicular to the molecular axis. Nonlinear optical susceptibilities of H2+ have been also obtained for different laser field directions. The time dependent Hartree-Fock results are compared to frozen core calculations for H2. Comparisons of present FE numerical results with previously published calculations show the FE method reproduces perturbative results and can also treat nonperturbatively the effect of intense short laser pulses as the method includes both bound and continuum electronic states. © 1995 American Institute of Physics.