Abstract
The present investigation concerns the analysis of the influence of short range orientational correlation on the thermodynamic properties of discotic-nematic liquid crystals. Two-site cluster approximation is applied to the orientational molecular coordinates to include the short range orientational correlation. The role of short range orientational order, dispersion interaction, molecular length-to-width ratio and pressure on the thermodynamic and orientational behaviour of discotic nematogens close to the discotic-nematic to isotropic transition are analysed. It is observed that the short range orientational order has a strong influence on the thermodynamic properties and that the transition properties of both the calamitic and discotic mesogens exhibit quite similar behaviour.