This paper discusses ways to simplify the problem of double ionization in a three-dimensional world by linearly polarized light. Symmetry reduces this problem to a five-dimensional one, and if electron spectra are not required, the calculation can be restricted to a small part of the configuration space where at least one of the electrons is close to the nucleus. In this case a mixed length-/ velocity-gauge representation seems optimal, and reduces the size of the problem such that it can be handled by a personal computer.

L. F. DiMauro , R. R. Freeman , K. C. Kulander

Muller, H. G. (2000). Solving the time-dependent Schrödinger equation in five dimensions. In L. F DiMauro, R. R Freeman, & K. C Kulander (Eds.), Multiphoton Processes: ICOMP VIII, 8th International Conference, Monterey California 3-8 October 1999 (pp. 257–264). AIP.