Abstract
An implementation of the non-collinear Alexander-Anderson model for itinerant electrons in magnetic systems is presented where self-consistency is reached for specified directions of the magnetic moments. This is achieved by means of Lagrange multipliers and a variational principle for determining the transverse and longitudinal components of the magnetic moments as well as the average number of d-electrons using direct optimisation. Various optimisation algorithms are compared and the limited memory Broyden-Fletcher-Goldfarb-Shanno algorithm is found to give the best performance. An application to antiferromagnetic Cr crystal is presented where spin-dynamics and curvature of the energy surface are calculated to compare results obtained with and without the constraints on the orientation of the magnetic moments.
| Original language | English |
|---|---|
| Pages (from-to) | 65-77 |
| Number of pages | 13 |
| Journal | Nanosystems: Physics, Chemistry, Mathematics |
| Volume | 11 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2020 |
Bibliographical note
Funding Information: This work was funded by the Icelandic Research Fund, the University of Iceland doctoral fund (AVI) and the Russian Science Foundation under grant No. 19-72-10138. Publisher Copyright: © 2020, ITMO University. All rights reserved.Other keywords
- Alexander-anderson model
- Constraints.
- Itinerant magnetism
- Non-stationary configurations