On the choice of basis functions to eliminate false roots of the quantization condition in quantum defect theory
Mark Sheard Child, Miyabi Hiyama · Journal of Physics B Atomic Molecular and Optical Physics · 2007
It is shown that the inherent arbitrariness in the construction of basis functions in quantum defect theory allows a choice that eliminates the occurrence of false roots of the quantization condition, with energies below the minimum of the channel potential. Comparisons are given with the well-known Ham procedure and with the more recent generalization to arbitrary fields by Jungen and Texier. The significance of the results for ab initio R matrix/MQDT studies is also discussed.