Spin spiral ground state of gamma-iron

Using density-functional theory we calculate the magnetic ground-state properties of gamma-Fe for a large set of spiral vectors and lattice constants. The effective single-particle equations are solved by means of an advanced version of the augmented spherical waves method which takes into account the full-shape potential and the intra-atomic noncollinearity of the magnetization. Together with the generalized gradient approximation the experimentally determined spiral magnetic ground state is reproduced successfully. Symmetry properties of the intra-atomic noncollinearity of the magnetization an analyzed and illustrated fur spiral magnetic structures. We conclude that gamma-Fe is an itinerant electron system possessing well-defined atomic moments.