Abstract
Energies of arbitrary small- and large-angle noncollinear excited magnetic configurations are computed using a highly accurate constrained density functional theory approach. Numerical convergence and accuracy are controlled by the choice of Lagrange multipliers entering the constraining conditions. The penalty part of the constrained energy functional at its minimum is shown to be inversely proportional to , enabling a simple, robust, and accurate iterative procedure to be followed to find a convergent solution. The method is implemented as a part of ab initio vasp package, and applied to the investigation of noncollinear B2-like and double-layer antiferromagnetic configurations of bcc iron, dimer, and amorphous iron. Forces acting on atoms depend on the orientations of magnetic moments, and the proposed approach enables constrained self-consistent noncollinear magnetic and structural relaxation of large atomic systems to be carried out.
6 More- Received 4 September 2014
- Revised 22 December 2014
DOI:https://doi.org/10.1103/PhysRevB.91.054420
Published by the American Physical Society