The physical model used in Fleur simulations is based on the (F)LAPW(+LO) method, but it is also possible to make use of an APW+lo description. The calculations employ the scalar-relativistic approximation for the kinetic energy operator.[7][8] Spin-orbit coupling can optionally be included.[9] It is possible to describe noncollinear magnetic structures periodic in the unit cell.[10] The description of spin spirals with deviating periodicity is based on the generalized Bloch theorem.[11] The code offers native support for the description of three-dimensional periodic structures, i.e., bulk crystals, as well as two-dimensional periodic structures like thin films and surfaces.[12] For the description of the exchange-correlation functional different parametrizations for the local density approximation, several generalized-gradient approximations, Hybrid functionals,[13] and partial support for the libXC library are implemented. It is also possible to make use of a DFT+U description.[14]
Features
The Fleur code can be used to directly calculate many different material properties. Among these are:
For the calculation of optical properties Fleur can be combined with the Spex code to perform calculations employing the GW approximation to many-body perturbation theory.[18] Together with the Wannier90 library it is also possible to extract the Kohn-Sham eigenfunctions in terms of Wannier functions.[19]
^Lejaeghere, K.; Bihlmayer, G.; Bjorkman, T.; Blaha, P.; Blugel, S.; Blum, V.; Caliste, D.; Castelli, I. E.; Clark, S. J.; Dal Corso, A.; de Gironcoli, S.; Deutsch, T.; Dewhurst, J. K.; Di Marco, I.; Draxl, C.; Dułak, M.; Eriksson, O.; Flores-Livas, J. A.; Garrity, K. F.; Genovese, L.; Giannozzi, P.; Giantomassi, M.; Goedecker, S.; Gonze, X.; Granas, O.; Gross, E. K. U.; Gulans, A.; Gygi, F.; Hamann, D. R.; Hasnip, P. J.; Holzwarth, N. A. W.; Iuşan, D.; Jochym, D. B.; Jollet, F.; Jones, D.; Kresse, G.; Koepernik, K.; Kucukbenli, E.; Kvashnin, Y. O.; Locht, I. L. M.; Lubeck, S.; Marsman, M.; Marzari, N.; Nitzsche, U.; Nordstrom, L.; Ozaki, T.; Paulatto, L.; Pickard, C. J.; Poelmans, W.; Probert, M. I. J.; Refson, K.; Richter, M.; Rignanese, G.-M.; Saha, S.; Scheffler, M.; Schlipf, M.; Schwarz, K.; Sharma, S.; Tavazza, F.; Thunstrom, P.; Tkatchenko, A.; Torrent, M.; Vanderbilt, D.; van Setten, M. J.; Van Speybroeck, V.; Wills, J. M.; Yates, J. R.; Zhang, G.-X.; Cottenier, S. (25 March 2016). "Reproducibility in density functional theory calculations of solids". Science. 351 (6280): aad3000. Bibcode:2016Sci...351.....L. doi:10.1126/science.aad3000. hdl:1854/LU-7191263. PMID27013736. S2CID206642768.
^Bode, M.; Heide, M.; von Bergmann, K.; Ferriani, P.; Heinze, S.; Bihlmayer, G.; Kubetzka, A.; Pietzsch, O.; Blügel, S.; Wiesendanger, R. (May 2007). "Chiral magnetic order at surfaces driven by inversion asymmetry". Nature. 447 (7141): 190–193. Bibcode:2007Natur.447..190B. doi:10.1038/nature05802. PMID17495922. S2CID4421433.
^Heinze, Stefan; von Bergmann, Kirsten; Menzel, Matthias; Brede, Jens; Kubetzka, André; Wiesendanger, Roland; Bihlmayer, Gustav; Blügel, Stefan (September 2011). "Spontaneous atomic-scale magnetic skyrmion lattice in two dimensions". Nature Physics. 7 (9): 713–718. Bibcode:2011NatPh...7..713H. doi:10.1038/nphys2045.
^Koelling, D D; Harmon, B N (28 August 1977). "A technique for relativistic spin-polarised calculations". Journal of Physics C: Solid State Physics. 10 (16): 3107–3114. Bibcode:1977JPhC...10.3107K. doi:10.1088/0022-3719/10/16/019.
^MacDonald, A H; Picket, W E; Koelling, D D (20 May 1980). "A linearised relativistic augmented-plane-wave method utilising approximate pure spin basis functions". Journal of Physics C: Solid State Physics. 13 (14): 2675–2683. Bibcode:1980JPhC...13.2675M. doi:10.1088/0022-3719/13/14/009.
^Heide, M.; Bihlmayer, G.; Blügel, S. (October 2009). "Describing Dzyaloshinskii–Moriya spirals from first principles". Physica B: Condensed Matter. 404 (18): 2678–2683. Bibcode:2009PhyB..404.2678H. doi:10.1016/j.physb.2009.06.070.
^Krakauer, H.; Posternak, M.; Freeman, A. J. (15 February 1979). "Linearized augmented plane-wave method for the electronic band structure of thin films". Physical Review B. 19 (4): 1706–1719. Bibcode:1979PhRvB..19.1706K. doi:10.1103/PhysRevB.19.1706.
^Weinert, M.; Wimmer, E.; Freeman, A. J. (15 October 1982). "Total-energy all-electron density functional method for bulk solids and surfaces". Physical Review B. 26 (8): 4571–4578. Bibcode:1982PhRvB..26.4571W. doi:10.1103/PhysRevB.26.4571.
^Yu, Rici; Singh, D.; Krakauer, H. (15 March 1991). "All-electron and pseudopotential force calculations using the linearized-augmented-plane-wave method". Physical Review B. 43 (8): 6411–6422. Bibcode:1991PhRvB..43.6411Y. doi:10.1103/PhysRevB.43.6411. PMID9998079.
^Klüppelberg, Daniel A.; Betzinger, Markus; Blügel, Stefan (5 January 2015). "Atomic force calculations within the all-electron FLAPW method: Treatment of core states and discontinuities at the muffin-tin sphere boundary". Physical Review B. 91 (3): 035105. Bibcode:2015PhRvB..91c5105K. doi:10.1103/PhysRevB.91.035105.