Our computation of the electronic structure of fcc Co has been accomplished with WIEN97.9. This is a spin-polarized LAPW first-principles calculation including spin-orbit interaction. In these calculations, the generalized gradient approximation was used to treat exchange and correlation and a basis set of 375 plane waves were used for each spin which includes additional local orbitals added to improve the quality of the empty final states. The Co was assumed to have a bulk tetragonally-distorted fcc structure with in-plane (x and y) lattice parameters that of Cu (3.615 A) and out-of-plane (z) one that is smaller (3.42 A). The Co was magnetized in-plane along the +x direction.

Using an fcc structure without the tetragonal distortion, our own calculation of the Co band structure is in consistent with other calculations in the literature. For the tetragonal distortion here, the main difference is one band with delta-5 down and one with delta-5 up character is split into two inequivalent bands due to the reduced symmetry.

Angle-integrated valence-band spectrum. The bottom curve shows the data with an inelastic background removed.

Calculated Density of States (DOS) from the band structure to the right. (a) spin up with primarily 4sp-like and (b)-(d) spin down 3d Fermi surfaces.