Benchmark Calculations of Atomic Data for Modelling Applications

In recent years, much progress has been achieved in calculating reliable cross-section datasets for electron scattering from atoms and ions, in particular quasi-one and quasi-two electron systems such as H, He, the alkalis, and the alkaline-earth metals. Until recently, however, accurate calculations of electron collisions with more complex targets, such as the heavy noble gases Ne$-$Xe, have remained a significant challenge to theory. In this talk, we will illustrate with a few examples how the $B$-spline $R$-matrix (BSR) method with non-orthogonal orbitals~[1-3] has been able to dramatically improve the quality of theoretical datasets for oscillator strengths~[4] as well as electron collisions with numerous targets, including the heavy noble gases~[5], and how these data were used successfully in modelling applications~[6]. The most recent extension of the method, the $B$-spline $R$-matrix with Pseudo-States (BSRMPS) approach, includes a large number of pseudostates in the close-coupling expansion, thereby allowing for the fully non-perturbative treatment of highly correlated processes such as ionization and even ionization with simultaneous excitation~[7]. \\[4pt] [1] O. Zatsarinny and K. Bartschat, J.~Phys. B~{\bf 37} (2004), 2173 and 4693. \\[0pt] [2] O. Zatsarinny, Comp. Phys. Commun. {\bf 174} (2006) 273.\\[0pt] [3] O. Zatsarinny and K. Bartschat, Phys. Rev. A {\bf 77} (2008) 062701.\\[0pt] [4] O. Zatsarinny and K. Bartschat, Phys. Scr. Rev. {\bf T134} (2009) 014020.\\[0pt] [5] K. Bartschat and O. Zatsarinny, Plasma Sources Sci. Technol. {\bf 20} (2011) 024012.\\[0pt] [6] D. Dodt, A. Dinklage, K. Bartschat, and O. Zatsarinny, New Journal of Physics {\bf 12} (2010) 073018.\\[0pt] [7] O. Zatsarinny and K. Bartschat, Phys. Rev. Lett. {\bf 107} (2011) 023203.