CORRELATED CAPPED SUBSYSTEM CALCULATIONS AS A WAY TO INCLUDE ELECTRONCORRELATION LOCALLY - A TEST FOR SUBSTITUENT EFFECTS ON BOND-ENERGIES

A new integrated technique employing the capped subsystem strategy of the IMOMO method is used as a way to include electron correlation (con figuration mixing) in a molecular subsystem without requiring a transf ormation to localized orbitals. We obtain good results for bond energi es that require a correlated treatment of at least part of the molecul e, and we include the effect of substituents in any part of the molecu le. An especially important result is that the method provides a conve nient and practical way to include electron correlation in a localized subsystem, while retaining the quantum mechanical electronic effects of uncorrelated substituents.