ABSTRACT In this work, the Kerr coefficients of isotropic and uniaxial nematic liquid crystals consisting of hard ellipsoid and hard prolate pear-shaped molecules were theoretically studied using classical density functional theory. A new analytical approximate expression for the direct correlation function of hard pear- shaped molecules is applied. Using the expansion coefficients of this direct correlation function, we calculated the structural parameters, compressibility factor, and excess free energy of the hard pear-shaped liquid crystals. In addition, using the restricted orientation model, one particle density of a confined hard pear- shaped liquid crystal is calculated. The limiting stabilities and estimated transition densities are in qualitative agreement with available data. The results confirm the validity of this approximate direct correlation function.