Multiphoton abovethreshold detachment of Li^{}: Exteriorcomplexscaling generalizedpseudospectral method for calculations of complexquasienergy resonances in Floquet formulation of timedependent densityfunctional theory
Abstract
We extend the exteriorcomplexscalinggeneralizedpseudospectral (ECSGPS) method [D. A. Telnov and S. I. Chu, Phys. Rev. A 59, 2864 (1999)] to the nonperturbative calculations of complexquasienergy resonances of manyelectron quantum systems within the Floquet formulation of timedependent densityfunctional theory (TDDFT) [D. A. Telnov and S. I. Chu, Chem. Phys. Lett. 264, 466 (1997)]. The ECSGPS technique appears very useful in TDDFTFloquet calculations where the exchangecorrelation potentials may exhibit quite complicated behavior as functions of the electron coordinates and cannot be easily treated by means of the uniformcomplexscaling techniques. We have applied this procedure to the study of onephoton detachment and twophoton dominant abovethreshold detachment of Li^{} negative ions. In the onephoton case, the photodetachment cross section has been calculated as a function of the photon energy with results in good agreement with the experimental data. In the twophoton case, both the partial detachment rates and electron angular distributions for the dominant and abovethreshold channels are presented for a range of laser field frequencies and intensities. Dramatic transformations of the angular distributions in the vicinity of the twophoton threshold are observed and analyzed.
 Publication:

Physical Review A
 Pub Date:
 October 2002
 DOI:
 10.1103/PhysRevA.66.043417
 Bibcode:
 2002PhRvA..66d3417T
 Keywords:

 32.80.Rm;
 32.80.Gc;
 31.15.Ew;
 Multiphoton ionization and excitation to highly excited states;
 Photodetachment of atomic negative ions;
 Densityfunctional theory