SOLID ANGLES .1. THE RADIAL PROFILE

The use of solid angles (OMEGA) has been extended to the calculation o f the solid angle of a region of an atom or groups of atoms (e.g. liga nds) as a function of distance from a common apex (e.g. a metal). This methodology permits the evaluation of a second dimension when describ ing the 'size' of a molecule as measured by cone or solid angles. This new measure is referred to as a radial profile. Radial profiles for s ome common ligands (e.g. 2,6-Me2C6H3NC, (t)BuNC, P(OMe)3, PPh3 etc.) h ave been determined. A comparison of two radial profiles, correspondin g to two ligands, permits a qualitative evaluation of the position of steric interaction between the two ligands.