Electric-dipole 4f(N)-4f(N) transition intensity parametrizations for lanthanides: an examination of multiple local minima

For most symmetries the standard parametrization of one-photon electric-dip ole transitions between crystal-field levels of the 4f(N) configuration of lanthanide ions gives the same predictions for several quite different para meter sets. An alternative parametrization scheme that provides separate pa rameters for each of the different polarization directions has been shown t o remove this anomaly. A second problem arises due to the fact that multipl e local minima may fit the data nearly equally well. Through a detailed ree xamination of a series of lanthanide oxydiacetate (LnODA, Ln = Nd, Sm, Eu, Dy, and Ho) systems using the new parametrization, we examine the multiple local minima problem, and attempt a determination of the robustness of the global parametrization minimum. (C) 2001 Elsevier Science B.V. All rights r eserved.