【Objective】Physical properties of the RE2Ti3Si4(RE=Gd,Tb,Dy,Ho and Er)are studied.【Methods】We present the structural,electronic structure,mechanical and thermodynamic properties of the RE2Ti3Si4(RE=Gd,Tb,Dy,Ho and Er)by using first-principles calculations based on the density functional theory(DFT).【Results】The calculated lattice constants of RE2Ti3Si4are all in good agreement with experimental data.The single crystal elastic constants of RE2Ti3Si4have been calculated,and the bulk,shear and Young's modulus ...