Are Crystal Phase Diagrams Predictable with Force Fields? Case of Benzene Polymorphs

The accurate prediction of the properties of materials under nonstandard or extreme conditions, such as the high pressure of ocean depths and the near-absolute zero (0 K) temperatures of space, has become increasingly important. The ability to predict crystal polymorphs that are realized at a given pressure P and temperature T would allow the calculation of a crystal phase diagram for any given substance, as well as the ability to forecast the properties of different phases under certain conditions, even prior to their synthesis. This would have a large effect on several fields of science and technology. We present an efficient approach to parametrizing and/or optimizing the parameters of force fields, which takes into account external conditions.