A Gauss-Radau-Laguerre discrete variable representation for use in continuum electron dynamics*

We report on implementing within a developed and established finite element discrete variable represenatation (FEM-DVR) a Gauss-Radau-Laguerre tail finite element as the last element that includes exterior complex scaling (ECS) to impose outgoing wave boundary conditions on treatments of processes involving continuum electrons.  Expanding upon the method of "infinite range" ECS (irECS) described in Phys. Rev. A 81, 053845 (2010), we describe the method for both one- and two-electron continuum processes.  In particular we highlight the final Radau-Laguerre finite element implications and advantages for treating problems involving low energy electrons, as well as applications in strong-field processes.