Electronic and mechanical properties of Cr2GeC with hybrid functional and correlation effects

We present a computational study of the MAX phase material Cr2GeC to obtain its crystal and electronic structure using density functional theory with various exchange-correlation functionals. While the GGA and GGA+U methods are giving a reasonable description of the lattice parameters, the hybrid functional (HSE06) is found to give too large values. Then, on the basis of our GGA+U calculations, the antiferromagnetic ordering is found to be the ground state. Furthermore, we study the charge distribution between the constituent elements of this compound and find that the simple ionic model fails to describe it due to the complex nature of this material. Finally, we conclude that the treatment of the correlated electrons is important for the correct description of this material.