Calculation of Magnetic Couplings in Hydrogen-Bonded Cu(II) Complexes Using Density Functional Theory

The performance of recent density fiinctionals for computation of molecular magnetic coupling constants (J) in hydrogen-bonded systems is evaluated. A survey of six Cu(II) dinuclear complexes is considered. The global accuracy trend is GGAs < meta-GGAs < hybrid-GGAs approximate to hybrid meta-GGAs. Hybrid meta-GGAs do not generally provide any improvement over well-established hybrid functionals such as B3LYP. It is also seen that spin projection values agree best with experiment if one uses functionals that either have large quantities of exact exchange such as B2PLYP or functionals with long-range Coulomb screening such as CAM-B3LYP or LC-omega PBE, thus suggesting that these provide a description that is free from self-interaction errors.