CALCULATION OF BOND-DISSOCIATION ENERGIES OF DIATOMIC-MOLECULES USINGBOND FUNCTION BASIS-SETS WITH COUNTERPOISE CORRECTIONS

Bond function basis sets combined with the counterpoise procedure are used to calculate the molecular dissociation energies D-e of 24 diatom ic molecules and ions. The calculated values of D-e are compared to th ose without bond functions and/or counterpoise corrections. The equili brium bond lengths r(e) and harmonic frequencies omega(e) are also cal culated for a few selected molecules. The calculations at the fourth-o rder Moller-Plesset approximation (MP4) have consistently recovered ab out 95-99% of the experimental values for D-e, compared to as low as 7 5% without use of bond functions. The calculated values of r(e) are ty pically 0.01 Angstrom larger than the experimental values, and the cal culated values of omega(e) are over 95% of the experimental values. (C ) 1996 John Wiley & Sons, Inc.