ERC StG project: Accuracy and precision for molecular solids

Molecular solids are materials with very peculiar properties, for example, water has an extremely rich phase diagram with at least 16 known solid phases. Ammonia as well has quite exotic high pressure phases that are expected to occur in the mantles of Neptune or Uranus. Many molecular solids also exhibit polymorphism, they can crystallise in different crystal structures at ambient conditions. Discovering possible polymorphs for a given compound is crucial for pharmaceutical industry as properties, such as the dissolution rate and thus bioavailability, can strongly differ between polymorphs.

Computational modelling greatly helps in understanding the different phases of molecular solids but obtaining reliable data for the prediction of stabilities of different phases remains a great challenge. The energy differences between different phases or polymorphs are tiny and many currently widely used methods are not accurate enough to describe them correctly. Methods which are accurate do often come with prohibitive computational cost and can’t be applied either.

The goal of this project is to develop methods which would allow us to obtain reliable binding energies of molecular solids. This will involve a combination of techniques develop for solid state calculations (mostly within the code VASP) with quantum chemistry approaches (using codes such as Molpro, Turbomole, or similar). The PhD candidate will thus gain a deep understanding of the methods which are being developed for the description of materials using quantum chemistry techniques.