TRANSCRIPTION OF THE RESULTS OF QUANTUM-CHEMICAL CALCULATIONS IN TERMS OF THE CLASSICAL NOTION OF MOLECULAR-STRUCTURES - THE CASES OF SOME SMALL CARBONYLS IN THE GROUND AND EXCITED-STATES

Quantum chemical valence parameters of several carbonyl molecules in t he ground and excited states are calculated by invoking the INDO-ortho gonal gradient method in an MC-SCF framework. These parameters are the n used to construct state-specific structural descriptions of these mo lecules in terms of superposition of several canonical structures. Pho tochemical reactivities of some of these molecules are sought to be ex plained on the basis of the picture that emerges.