First-principles study on the elastic property of hexagonal alunite

In this paper, we have predicted the structural and elastic characteristics of KAl3(SO4)2(OH)6 compounds through the method of density functional theory within the generalized gradient approximation (GGA) and Local Density Approximation (LDA) using the CASTEP package. The calculated equilibrium lattice parameters, the elastic property, anisotropy factor, Poison's ratio, Young's modulus, sound velocities and Debye temperature for KAl3(SO4)2(OH)6 have been calculated and compared with the available experimental data. From these results, this compound behaves as a brittle material and has a good thermal conductivity.