The B-spline R-matrix method for electron and photon collisions with atoms and ions

We describe the recently developed B-spline R-matrix method for electron and photon collisions with atoms and ions. The completeness of the B-spline basis ensure that no Buttle correction is needed for the R-matrix elements. Another distinguishing feature of the present method is the use of non-orthogonal orbitals to construct the target description and to represent the scattering functions. This allows us to employ highly correlated target wavefunctions without any inconsistency between the continuum and bound parts of the close-coupling expansion. Recent applications of the method for accurate calculations of low-energy electron scattering from Ne and near-threshold photodetachment of O- are presented.