Obituary
It is with great sadness and sorrow that we have learnt about the sudden and
untimely death of our colleague, Prof. Dr. Tom Ziegler. Tom was a bright scientist
and one of the founders and pioneers of density functional theory. Tom has always
supported and encouraged new developments and always took an active part in
advancing and promoting them. Tom’s recent research on constricted variational
density functional theory holds considerable promise for the field of quantum
theoretical modeling of excited electronic states, and one of the latest accounts of
these developments is published in this book. Tom will be sorely missed by his
colleagues and the entire community of quantum theoretical chemists.