Abstract
Employing Born's theory of crystal lattices, the elastic constants of fluorspar have been evaluated theoretically. Besides the coulomb forces, repulsive forces between nearest neighbour calcium and fluorine atoms and fluorine-fluorine atoms have been assumed and the constants of the repulsive energy were evaluated from the equilibrium condition, the experimentally determined compressibility and the principal Raman frequency of fluorspar. The experimental values of c11, c12 and c44 are in fair agreement with the theoretically calculated values. Born's theory gives the sign of c12-c44 for fluorspar correctly but the theoretically calculated value of c12-c44 is only about half the experimentally observed value.