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The x-ray spectra resulting from single-electron capture in charge-exchange collisions of Nel0+ with He and Ne atoms are investigated for the projectile energy of 4.54 keV/u using the two-center atomic-orbital close-coupling method. The calculated spectra of the Ne9+ ion produced in Ne10+ + He and Nel0+ + Ne election-capture collisions have, generally speaking, the same level of agreement with experimental measurements as those calculated previously by the classical trajectory Monte Carlo method, indicating that multi-electron-capture processes, particularly in the case of the Nel0+ 4- Ne system, significantly affect the considered spectra. The effects of two-electron capture on the spectral line intensity have been demonstrated qualitatively by using the binomial statistics and independent particle model for the target outer-shell electrons. The role of multi-electron-capture processes in the Nel0+ 4- Ne collision system needs further attention. [ABSTRACT FROM AUTHOR]

The nonradiative charge-transfer processes for the Be3+(ls) + H(Is) collisions are investigated by the quantummechanical molecular orbital close-coupling" method in the energy range of 0.01-10 keV/u. The radiative charge-transfer cross sections are calculated by the optical potential and semiclassical methods in the energy range 10-6--10³ eV/u. The needed molecular data are obtained by the ab initio multireference single- and double-excitation configuration interaction method. Total and state-selective cross sections are presented and compared with other available theoretical data. Our calculation agrees well with the atomic orbital close-coupling results of Liu et al. [L. Liu, D. Jakimovski, J. G. Wang, and R. K. Janev, J. Phys. B 43, 144005 (2010)], but there exist some discrepancies with the semiclassical molecular orbital close-coupling results of Shimakura [N. Shimakura, J. Phys. B 21, 2485 (1988)]. The present results show that the capture to Si2+(1s3l) states is dominant in the whole energy range with the exception of a narrow range of 2-4 keV/u. Rotational couplings play an important role not only in the state-selective cross sections, but also in the total charge-transfer results. At energies below 40 eV/u, the radiative charge transfer exceeds the nonradiative process. [ABSTRACT FROM AUTHOR]

The nonradiative charge-transfer processes of Li++Na(3s) collisions have been investigated by using the fully quantum-mechanical molecular-orbital close-coupling method and the two-center atomic-orbital close-coupling method for the energy range of 10-4-2keV/u and 0.2-10keV/u, respectively. The radiative charge-transfer, radiative decay, and radiative-association processes have been studied by employing the fully quantum, optical-potential, and semiclassical methods for the energy range of 2×10-10-110eV/u. The nonradiative charge-transfer processes dominate the collisions for energies above 0.2 eV/u while radiative decay processes dominate in the lower-energy region. Especially, we found that the radiative-association process is more important than the radiative charge-transfer process when E<2×10-2eV/u. The rate coefficients of nonradiative and radiative processes are also given for the temperature range of 3×104-2×109K and 10-6-10³K, respectively. [ABSTRACT FROM AUTHOR]

The time-dependent density functional theory is applied to investigate the charge transfer and electron-loss processes during He2+-Ar collisions in the energy range of 4-300 keV/amu. A coordinate space translation technique is employed to focus our investigation on some certain space of interest such as the regions around the projectile or target. It is shown that both charge transfer and electron-loss processes are important in the considered energy range. One-electron-capture processes dominate charge transfer with the cross sections one to two orders of magnitude larger than two-electron-capture cross sections. The ionization cross sections decrease with increasing the number of ionized electrons. The calculated cross sections are in excellent agreement with available experimental and theoretical results. Evolution of electron density is also presented to explore interactions between the electrons as well as the correlation between the projectile and target during the collisions. [ABSTRACT FROM AUTHOR]