The unique properties and applications of transition metal compounds have long fascinated both physicists and chemists. This volume presents theoretical and experimental studies for a deeper understanding of the electronic and vibronic properties of these compounds. In particular, an introduction into properties of spin sublevels of dd*, dA*, and AA* states is given, and a modern ligand field theory based on the Angular Overlap Model is presented. In experimental case studies it is shown how to characterize different types of electronic transitions using modern methods of laser spectroscopy. Consequences of spin-orbit coupling, zero-field splittings, spin-lattice relaxations, chromophore-matrix interactions, Herzberg-Teller/Franck-Condon activities, and localization/delocalization properties are treated.