Generalization of the Approach to Other Interactions

While the earlier work on close S--0 contacts and halogen X---0 interactions provides specific parameters that can be used to improve force field treatment of certain interactions in small molecules, there are potentially many other interactions that could be amended with a special force field treatment. The approach presented earlier offers a straightforward way to improve specific aspects of a force field for the generation of accurate small-molecule conformations. The approach can be broken down into the following three steps  

Improvement of the force field using QM and experimental data 

Identification of the problematic interaction In many cases the deficiency in the force field will be clear. For example, in the case of the close S - O interactions it was 

FIGURE 4.10 Distribution of C1---0 distances from the CSD and different minimization methods. 

IMPROVING FORCE FIELD PARAMETERS FOR SMALL-MOLECULE 

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