This book about a chronicle about the development of electronic structure theories for transition metal complexes orbital models and electronic structure theory, sturmians and generalized sturmians in quantum theory, chemistry as a “manifestation of quantum phenomena” and the born–oppenheimer approximation?, from ligand field theory to molecular collision dynamics : a common thread of angular momentum, a modern first-principles view on ligand field theory through the eyes of correlated multireference wavefunctions, and the phase rule : beyond myopia to understanding.