Theoretical search for new permanent magnets with no rare earth atoms

We use the density functional theory and Quasiparticle Self-Consistent GW approximation to investigate the crystal and electronic structure, magnetic moment, anisotropy, and exchange coupling of Fe$_{16}$N$_2$, Fe$_{13}$Al$_3$, Co$_7$Hf and Zr$_2$Co$_{11}$. Both methods show similar results for magnetization and electronic structure. The experimentally unknown crystal structures of Co$_7$Hf and Zr$_2$Co$_{11}$ are obtained using structural optimization. We also discuss possible usage of these materials as permanent magnets.