Methods for Modeling Biomolecules

At the other extreme is a trend toward the increasing use of orbital-based techniques, particularly QM/MM calculations (Chapter 23). These orbital-based techniques are needed to accurately model the actual process of chemical bond breaking and formation. 

The first step in designing a new compound is to find compounds that have even a slight amount of usefulness for the intended purpose. These are called lead compounds. Once such compounds are identified, the problem becomes one of refinement. Computational techniques are a fairly minor part of finding lead compounds. The use of computer-based techniques for lead compound identification is usually limited to searching databases for compounds similar to known lead compounds or known to treat diseases with similar causes or symptoms. 

---