An improved method for the computation of ligand steric effects based on solid angles.

An improved algorithm has been designed to characterize ligand interactions in organometallic and coordination complexes in terms of the percentage of the metal coordination sphere shielded by a given ligand. The computations for ligand solid angles are performed numerically and employ introduced atomic radii that are larger than covalent but smaller than van der Waals radii. This approach enables facile evaluation of steric congestion in the metal coordination sphere, quantification of unfavorable interligand contacts, and in some cases prediction of the complex composition or ligand coordination on purely geometrical grounds.