Hans-Herbert Schmidtke was a prolific theoretical chemist. His scientific work and life still influences great achievements on ab initio methods. On January 22, 2023 Hans-Herbert Schmidtke, Professor Emeritus of theoretical chemistry at the University of Düsseldorf, died in a hospital near Erkrath, Germany. He was internationally renowned scientist known for his work correlating highly resolved absorption and emission spectra of coordination compounds with their electronic and geometric structures using ligand field theory. He started his studies in chemistry at the University of Frankfurt in 1951 where he completed his diploma in 1956. Schmi...