SEMIEMPIRICAL QUANTUM-CHEMICAL METHOD FOR PREDICTING MASS-SPECTROMETRIC FRAGMENTATIONS

Energy partitioning (decomposition of the total energy into one- and t wo-center contributions) performed at the MNDO level of theory has bee n found to be very useful for interpreting and predicting mass spectro metric fragmentation processes. The changes in bond contributions duri ng vertical ionization (from either the HOMO or one of the next-to-HOM O's) can be used to predict the main primary bond cleavages observed i n the mass spectra of organic molecules.