S. Yanagisawa et al., An investigation of density functionals: The first-row transition metal dimer calculations, J CHEM PHYS, 112(2), 2000, pp. 545-553
The performance of different density functional theory (DFT) methods was in
vestigated in the calculations of the bond length and the binding energy of
the first-low transition metal dimers. The 4s-3d interconfigurational ener
gies and 4s and 3d ionization potentials were also calculated for the first
-row transition metal atoms. In general, the hybrid DFT method, B3LYP, yiel
ds the bond lengths that are too short compared to the experimental ones. I
n contrast, the optimized bond lengths by nonhybrid DFT methods such as BOP
or PW91 are in good agreement with the experiment. It was also found that
nonhybrid DFT methods overestimate the binding energies, because they have
a tendency to overstabilize the electron configurations that contain the at
omic and molecular orbitals in a higher angular momentum open shell. The hy
brid DFT method yields more accurate binding energies, but it estimates rat
her poor energy gaps between states whose spin multiplicity is quite differ
ent. (C) 2000 American Institute of Physics. [S0021-9606(00)31002-9].