Introducing the coupled-clusters theory to the amorphous world of liquids and their molecular simulations

Amorphous molecular materials are ubiquitous ranging from drugs over semiconductors to solvents. Large predictive capabilities of quantum-chemical simulations of structural and thermodynamic properties of such materials have remained out of reach for long due to their immense computational costs. This study introduces a novel fragment-based ab initio Monte Carlo (FraMonC) simulation technique to overcome these prohibitive costs, to enable ab initio predictions of properties of molecular liquids or molecular glasses, and to minimize the amount of a priori required empiric inputs for such simulations. Focus on individual cohesive interactions within the bulk, and their importance sampling enables to exploit very accurate electron-structure methods, such as the coupled-clusters theory, the direct use of which for molecular simulations of thermodynamic properties for liquids is unprecedented. It promises a very high accuracy of the simulations when compared to established classical or quantum-chemical models that are commonly used to model material properties.