Electric-dipole 4f(N)-4f(N) transition intensity parametrizations for lanthanides: multiple indistinguishable parameter sets and 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 removes this ano maly. A second problem arises due to the fact that multiple local minima ma y fit the data nearly equally well. Through a detailed reexamination of the previously well-studied system NdODA, we examine and attempt to resolve th is local minima problem. (C) 2000 Elsevier Science S.A. All rights reserved .