ABSTRACT
This chapter describes general features associated with the packing of molecular materials based on geometric considerations. The link between these packing motifs and intermolecular interactions will be established through lattice energy calculations. Any approach to use theoretical methods to help determine or indeed predict crystal structures must take into account the balance between intra- and intermolecular interaction energies present in crystal lattice. Theoretical studies of molecular and calculated solid state structures or experimental structures determined by X-ray or neutron diffraction can generate a vast amount of data which has to be visualized and analyzed often in three dimensions. The use of a combination of high-resolution X-ray diffraction and theoretical methods can provide structural information on molecular materials comparable with traditional single-crystal methods. Molecular mechanics provides a route to accurate and reliable molecular structure information on larger systems. Molecular orbital methods can be employed across a wider range of molecular classes with a greater confidence than is possible by molecular mechanics.
