First-principles calculations for elastic properties of rutile TiO 2 under pressure

This paper studies the equilibrium structure parameters and the dependences of the elastic properties on pressure for rutile TiO 2 by using the Cambridge Serial Total Energy Package (CASTEP) program in the frame of density functional theory. The obtained equilibrium structure parameters, bulk modulus B 0 and its pressure derivative B 0 are in good agreement with experiments and the theoretical results. The six independent elastic constants of rutile TiO 2 under pressure are theoretically investigated for the first time. It is found that, as pressure increases, the elastic constants C 11 , C 33 , C 66 , C 12 and C 13 increase, the variation of elastic constant C 44 is not obvious and the anisotropy will weaken.