Complete description of the magnetic ground state in spinel vanadates

We explore a source-free local spin density approximation (LSDA)+U functional within density functional theory for its capabilities in describing noncollinear spin textures; capturing the noncollinear magnetic ground state of the spinel vanadates AV2O4 (A=Mn, Fe, and Co) remains an outstanding challenge for state-of-the-art ab initio methods. We demonstrate that both the noncollinear spin texture, as well as the magnitude of local moments, are captured, provided the source term (i.e., magnetic monopole term) is removed from the exchange-correlation magnetic field BXC. This suggests that for treatment of strongly correlated magnetic materials within the LSDA+U method the subtraction of the unphysical magnetic monopole term from the BXC is essential.