Abstract
In this paper, interatomic interactions, zone-center phonon frequencies, mechanical properties, sound velocities and Debye temperature of indium thiospinels MIn2S4 (M = Cd, Zn and Mg) have been calculated using rigid-ion model. We found that the first neighbor interaction is stronger than the second neighbor interaction. We have compared our calculated results with the available experimental and theoretical data and find good agreement with the experimental results.