Applicability of the Strongly Constrained and Appropriately Normed Density Functional to Transition-Metal Magnetism

We find that the recently developed self-consistent and appropriately normed meta-generalized gradient approximation, which has been found to provide highly accurate results for many materials, is, however, not able to describe the stability and properties of phases of Fe important for steel. This is due to an overestimated tendency toward magnetism and exaggeration of magnetic energies, which we also find in other transition metals.

Figure 1

FSM energy for bcc Fe at the experimental lattice constant of 2.86 Å, on a per atom basis. The dashed lines are the energies of non-spin-polarized fcc Fe, at the optimized lattice parameter for the different functionals. The small dots indicate the minimum energy points.

Figure 2

LDA, PBE, and SCAN FSM energy in meV/atom for bcc and fcc Fe as functions of lattice parameter and spin moment.

Figure 3

FSM calculations of the magnetic energy of transition metal elements with the LDA, PBE and SCAN functionals.