APPLICATION OF GENERALIZED GRADIENT-CORRECTED DENSITY FUNCTIONALS TO IRON

The electronic structure and total energy of iron are calculated for the fcc and bcc crystal structures using the linear muffin-tin orbital method in the atomic-sphere approximation (LMTO-ASA). Results obtained using the recently proposed gradient-corrected density functional of Perdew and Wang (PW91) are presented and are compared to those obtained with the local- (spin-) density approximation (LSDA). It is found that substantially better agreement with measured quantities for both structural and electronic properties is achieved with the PW91 approximation than with the LSDA. The effects of including corrections to the ASA are briefly discussed.