In this Appendix we present the equations for the gradients of the stereochemical terms. Most of these are derived by straightforward algebra and no details will be given. Because of the assumptions used in the case of planarity restraints these equations are derived explicitly.
The stereochemistry terms are of the following form [cf. equation (2) in the main text]:
The gradients are of the form
Only the portion of (44) unique to each type of restraint (i.e. the derivative of the calculated quantity with respect to the parameters of the model) will be listed in each of the following sections. In each section the coordinates are assumed to be expressed in an orthogonal system.
