B-spline Breit-Pauli R-matrix calculations for electron collisions with neon atoms

We have extended the B-spline R-matrix method of Zatsarinny and Froese Fischer (2000 J. Phys. B: At. Mol. Opt. Phys. 33 313) to account for relativistic effects by including terms of the Breit-Pauli Hamiltonian in the inner region of the R-matrix box. The new computer code has been applied successfully to the treatment of e-Ne collisions, also using a variety of non-orthogonal valence orbitals to account for the strong term dependence in the one-electron orbitals. Using non-orthogonal basis sets avoids the need for pseudo-orbitals to improve upon the target description and virtually eliminates pseudo-resonance problems. While the present results are in overall satisfactory agreement with earlier results from a standard R-matrix calculation (Zeman and Bartschat 1997 J. Phys. B: At. Mol. Opt. Phys. 30 4609), a thorough comparison with recent experimental data for angle-integrated and angle-differential cross sections reveals substantial improvements of the present calculations in detail.