1. M. K. Scheller and L. S. Cederbaum are at the Universität Heidelberg, Theoretische Chemie, Institut für Physikalische Chemie, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany.
2. R. N. Compton is at Oak Ridge National Laboratory, Oak Ridge, TN 378312-6125, and is in the Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600, USA.