The book presents a detailed study of conformation and interactions in some mesogenic molecules. With help of computed pair potentials using multicentre multi pole interactions mesogenic properties were predicted. The role asymmetric pair potential for the mesogenic behavior is nicely explained. The relationship between smectic phases, nematic phases & Isotropic phases and mode of intermolecular interaction were explained based on computed data. A simple model to calculate nematic to isotropic transition temperature were presented and trend of even-odd effect in transition temperature explained using intermolecular interactions energies.