Developing realistic and precise models of the electronic properties of organic molecular crystals is crucial for understanding the full range of strongly correlated phases that they exhibit. By using \textit{ab initio} model construction methods, one can obtain unbiased non-interacting models of such systems from density functional theory, upon which one can base further (many-body) models. We will discuss the utility and advantages of \textit{ab initio} model construction using Wannier orbitals. We will briefly review the approach, and then explain why it is so well suited to molecular crystals in particular. We discuss the \textit{ab initio} construction of both non-interacting and interacting Hamitonians, and highlight recent examples where such first principles models lead to importantly different results than fitted models.
@article{arxiv.1508.07735,
title = {Deriving \textit{ab initio} model Hamiltonians for molecular crystals},
author = {A. C. Jacko},
journal= {arXiv preprint arXiv:1508.07735},
year = {2015}
}