ABSTRACT
On one hand, comparative molecular surface analysis (CoMFA) implies calculations of eld values on the numerous nodes of the lattice. On the other hand, the expression chosen for the potentials is not without problems. Lennard-Jones potentials are very steep near the atomic positions. Hence, the need for very precise alignment rules (a small variation in position leading to largely different values of the steric eld) and the choice, in order to treat simultaneously the steric and electrostatic components, of (somewhat arbitrary) scaling factors, which leads to some information loss. As a consequence, contour maps sometimes present singularities, making their interpretation unclear. Furthermore, limiting structural inšuences to steric and electrostatic contributions may seem a rather crude approximation (although introduction in CoMFA of additional variables and other elds was proposed).
