No abstract

The cross section , angular-distribution parameter ␤, and spin-polarization parameters ͕ , , ͖ of photoelectrons for neutral beryllium are calculated in the multiconfiguration relativistic random-phase approximation theory. Precise energies and widths of all five Rydberg series of doubly excited states ͑2pns͒ 1 P 1 o , ͑2pns͒ 3 P 1 o , ͑2pnd͒ 1 P 1 o , ͑2pnd͒ 3 P 1 o , and ͑2pnd͒ 3 D 1 o are given. Experimental studies of the angular distribution and spin polarization of photoelectrons are suggested to obtain information on energies and widths of states, which cannot be obtained from total cross-section measurements.

We examine the performance of our recently developed LFAs-PBE exchange-correlation (XC) potential [C.-R. Pan, P.-T. Fang, and J.-D. Chai, Phys. Rev. A, 2013, 87, 052510] for the highorder harmonic generation (HHG) spectra and related properties of H + 2 molecules aligned parallel and perpendicular to the polarization of an intense linearly polarized laser pulse, employing the real-time formulation of time-dependent density functional theory (RT-TDDFT). The results are compared with the exact solutions of the time-dependent Schrödinger equation as well as thoseobtained with other XC potentials in RT-TDDFT. Owing to its correct (−1/r) asymptote, the LFAs-PBE potential significantly outperforms conventional XC potentials for the HHG spectra and the properties that are sensitive to the XC potential asymptote. Accordingly, the LFAs-PBE potential, which has a computational cost similar to that of the popular Perdew-Burke-Ernzerhof (PBE) potential, can be very promising for the study of the ground-state, excited-state, and timedependent properties of large electronic systems, extending the applicability of density functional methods for a diverse range of applications.

No abstract