Ab initio study on structural and electronic properties of ReOFeAs (Re: La, Sm, Nd, Ce, Gd) under hydrostatic pressure

Abstract

This study employs density-functional theory (DFT) to probe the effect of external pressure on the pristine ReOFeAs (Re: La, Sm, Nd, Ce, Gd). As-Fe-As angle depends non-linearly on pressure. In addition, As-Fe-As angle and As-distance from Fe-layer in SmOFeAs and NdOFeAs obtain a configuration met in unconventional superconductors at around 10 GPa. Last, the structural variations coincide with changes in the electronic density of states which stem from the Re-4f and Fe-3d orbitals.