First principles simulation of the magnetic and structural properties of iron.

We have implemented non-collinear GGA and a generalized Blochs theorem to simulate unconmensurate spiral arrangements of spins in a Density Functional Theory code based on localized wave functions. We have subsequently performed a thorough study of the different states of bulk Iron. We determine the minimal basis set required to obtain reliable orderings of ground and excited states. We find that the most stable fcc phase is a spiral with an equilibrium lattice constant 3.56 Å