Magnetic ground state of Cr in density-functional theory

We present ab initio density-functional investigations of static long-period spin-density waves (SDWs) in chromium. Calculations were performed in the local-spin-density approximation with and without the generalized-gradient approximation, using both projector-augmented wave and muffin-tin-orbital techniques. The results show that for all cases the ground state of Cr is predicted to be of commensurate antiferromagnetic order, longitudinal SDWs lead to an increased total energy. The excitation energies associated with SDW formation are within the range of thermal energies even well below the Néel temperature. Structural relaxation of the SDW reveals that the stress relaxation has no significant effect on the energetics of the SDW phase. A possible scenario for the origin of the observed SDW state is developed.