Density functional theory and molecular bonding. III. Ironhyphen;series dimers

摘要

Binding energy curves for lowhyphen;lying states of the 3dhyphen;dimers K2ndash;Cu2have been calculated using the density functional formalism with a local spinhyphen;density approximation for the exchangehyphen;correlation energy. Binding energy trends across the series are discussed as a competition between chemical bond formation and the reduction in spinhyphen;degeneracy which accompanies it. At the ends of the series, satisfactory agreement is found with available spectroscopic data. Both experimental and calculated binding energies show pronounced minima towards the center of the series, at Mn2and Cr2, respectively. Discrepancies in binding energy trends are attributed to an incorrect description ofsndash;dtransfer inherent in the LSD approximation.