Comparison of the accuracy of DFT methods for reactions with relevance to nitrogenase

Abstract We have studied the accuracy of 16 different density functional theory methods to reproduce experimental data for bond lengths, angles, vibrational frequencies, as well enthalpies and entropies binding N 2 , H CO hydride ions various transition-metal complexes (with Fe, Ni, Cr, Mo W) with relation nitrogenase. show that generalized gradient approximation functionals give better structure-related parameters, whereas hybrid often energies. However, BLYP B97D seem reasonably accurate results both types properties. Geometries are converged split-valence basis sets, but energies frequencies (and therefore also thermal corrections) in general require a set triple-zeta quality. Dispersion corrections important obtain (contributing by up 57 kJ mol −1 ), structures.