Comparisons of different force fields in conformational analysis and searching of organic molecules: A review

This review aims to examine literature where different force fields are compared by their performances in conformational analysis and searching of organic molecules. Conformational analysis studies are those where energies and/or geometries of conformers are evaluated with force fields; the closer the values are to experiment or ab initio calculations, the better the force field performance. In conformational searching, an algorithm alters the geometry of a chemical system, followed by force field energy minimisation, then the process repeats, ideally until all conformations of the system are found. For conformational analysis, MM2, MM3 and MMFF94 often showed strong performances and their use is recommended. The polarisable AMOEBA force field consistently had strong performance and further comparisons including AMOEBA are advised. UFF showed very weak performance and is not recommended. For conformational searching, a distinct lack of comparisons were found, and the need for more work is emphasised.