GERT D. BILLING is Professor of Theoretical Chemistry at the University of Copenhagen. He serves as referee and sits on the editorial boards of numerous professional journals and has been a visiting professor at numerous universities and research institutes worldwide. Professor Billing is author or coauthor of over 200 published papers and 150 conference presentations.
KURT V. MIKKELSEN is Associate Professor in the Department of Chemistry, Århus University, Denmark. He has been an invited lecturer at dozens of universities and conferences in Europe and the United States, and has published 60 papers in international journals.