Perhaps better to say that the ferromagnetic starting point converges to a ferromagnetic fixed point. You might be able to find a local ferromagnetic solution by first converging sonewhat using runfsm, then switching to runsp.
--- Prof Laurence Marks "Research is to see what everyone else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi www.numis.northwestern.edu On Tue, Apr 16, 2019, 09:53 Fecher, Gerhard <[email protected]> wrote: > It just means that the ferromagnetic state is not stable, > the solutions for the ferrimagnetic state are identical, besides the signs > of the magnetic moments (what doesn't matter). > > Ciao > Gerhard > > DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: > "I think the problem, to be quite honest with you, > is that you have never actually known what the question is." > > ==================================== > Dr. Gerhard H. Fecher > Institut of Inorganic and Analytical Chemistry > Johannes Gutenberg - University > 55099 Mainz > and > Max Planck Institute for Chemical Physics of Solids > 01187 Dresden > ________________________________________ > Von: Wien [[email protected]] im Auftrag von Penny, > Charles [[email protected]] > Gesendet: Dienstag, 16. April 2019 10:29 > An: [email protected] > Betreff: [Wien] Magnetic moments converging in a different direction to > the one they are defined > > Dear all, > > > I am running spin-polarised calculations on a range of iron-spinel > structures (namely, magnetite (Fe3O4), maghemite (gamma-Fe2O3) and greigite > (Fe3S4)) with the objective of calculating magnetic exchange energies in > these minerals. This requires calculating total energies of lot of > different spin configurations. This process has worked well for magnetite > and maghemite, but I have encountered a problem with greigite. > > > When I run a calculation on a spin configuration of greigite that isn’t > the ferrimagnetic ground state (e.g. a ferromagnetic configuration) the > calculation converges to the ferrimagnetic solution, with the sublattice > moments pointing in opposing directions. > > > In the examples below, I have used a low-symmetry unit cell with eight > unique iron atoms which allows me to calculate the required number of spin > configurations for estimating J_ij. Atoms 1-4 correspond to A site iron > atoms in the spinel structure, atoms 5-8 correspond to B site iron atoms > and atoms 9-16 are sulphur atoms. In a ferrimagnetic system the A and B > sites have opposing moments and sulphur atoms are non-magneitc. > > > When I define a ferrimagnetic spin configuration, the calculation proceeds > as expected, with the final moments looking like; > > > rkmax_8_k_500.scf::MMINT: MAGNETIC MOMENT IN INTERSTITIAL = -0.05116 > > rkmax_8_k_500.scf::MMI001: MAGNETIC MOMENT IN SPHERE 1 = 2.47349 > > rkmax_8_k_500.scf::MMI002: MAGNETIC MOMENT IN SPHERE 2 = 2.47348 > > rkmax_8_k_500.scf::MMI003: MAGNETIC MOMENT IN SPHERE 3 = 2.47348 > > rkmax_8_k_500.scf::MMI004: MAGNETIC MOMENT IN SPHERE 4 = 2.47348 > > rkmax_8_k_500.scf::MMI005: MAGNETIC MOMENT IN SPHERE 5 = -3.01699 > > rkmax_8_k_500.scf::MMI006: MAGNETIC MOMENT IN SPHERE 6 = -3.01699 > > rkmax_8_k_500.scf::MMI007: MAGNETIC MOMENT IN SPHERE 7 = -3.01699 > > rkmax_8_k_500.scf::MMI008: MAGNETIC MOMENT IN SPHERE 8 = -3.01699 > > rkmax_8_k_500.scf::MMI009: MAGNETIC MOMENT IN SPHERE 9 = -0.03675 > > rkmax_8_k_500.scf::MMI010: MAGNETIC MOMENT IN SPHERE 10 = -0.03675 > > rkmax_8_k_500.scf::MMI011: MAGNETIC MOMENT IN SPHERE 11 = -0.03675 > > rkmax_8_k_500.scf::MMI012: MAGNETIC MOMENT IN SPHERE 12 = -0.03675 > > rkmax_8_k_500.scf::MMI013: MAGNETIC MOMENT IN SPHERE 13 = -0.03675 > > rkmax_8_k_500.scf::MMI014: MAGNETIC MOMENT IN SPHERE 14 = -0.03675 > > rkmax_8_k_500.scf::MMI015: MAGNETIC MOMENT IN SPHERE 15 = -0.03675 > > rkmax_8_k_500.scf::MMI016: MAGNETIC MOMENT IN SPHERE 16 = -0.03675 > > rkmax_8_k_500.scf::MMTOT: SPIN MAGNETIC MOMENT IN CELL = -14.88108 > > > Final energy; > > > rkmax_8_k_500.scf::ENE : ********** TOTAL ENERGY IN Ry = > -43322.30312592 > > > However, when I define a ferromagnetic spin configuration the system > converges to a ferrimagnetic solution with final moments; > > > k_500_rkmax_8.scf::MMINT: MAGNETIC MOMENT IN INTERSTITIAL = 0.05118 > > k_500_rkmax_8.scf::MMI001: MAGNETIC MOMENT IN SPHERE 1 = -2.47348 > > k_500_rkmax_8.scf::MMI002: MAGNETIC MOMENT IN SPHERE 2 = -2.47347 > > k_500_rkmax_8.scf::MMI003: MAGNETIC MOMENT IN SPHERE 3 = -2.47346 > > k_500_rkmax_8.scf::MMI004: MAGNETIC MOMENT IN SPHERE 4 = -2.47346 > > k_500_rkmax_8.scf::MMI005: MAGNETIC MOMENT IN SPHERE 5 = 3.01697 > > k_500_rkmax_8.scf::MMI006: MAGNETIC MOMENT IN SPHERE 6 = 3.01697 > > k_500_rkmax_8.scf::MMI007: MAGNETIC MOMENT IN SPHERE 7 = 3.01697 > > k_500_rkmax_8.scf::MMI008: MAGNETIC MOMENT IN SPHERE 8 = 3.01697 > > k_500_rkmax_8.scf::MMI009: MAGNETIC MOMENT IN SPHERE 9 = 0.03675 > > k_500_rkmax_8.scf::MMI010: MAGNETIC MOMENT IN SPHERE 10 = 0.03675 > > k_500_rkmax_8.scf::MMI011: MAGNETIC MOMENT IN SPHERE 11 = 0.03675 > > k_500_rkmax_8.scf::MMI012: MAGNETIC MOMENT IN SPHERE 12 = 0.03675 > > k_500_rkmax_8.scf::MMI013: MAGNETIC MOMENT IN SPHERE 13 = 0.03675 > > k_500_rkmax_8.scf::MMI014: MAGNETIC MOMENT IN SPHERE 14 = 0.03675 > > k_500_rkmax_8.scf::MMI015: MAGNETIC MOMENT IN SPHERE 15 = 0.03675 > > k_500_rkmax_8.scf::MMI016: MAGNETIC MOMENT IN SPHERE 16 = 0.03675 > > k_500_rkmax_8.scf::MMTOT: SPIN MAGNETIC MOMENT IN CELL = 14.88103 > > > Final energy is the same as in the ferrimagnetic case; > > > k_500_rkmax_8.scf::ENE : ********** TOTAL ENERGY IN Ry = > -43322.30312578 > > > Charge distance looks like it converges in both cases. Note that whilst > the two calculations have the same saved name, they are in completely > different CASE files. To outline my procedure, I initially call, > > > instgen -ask > > > And define the moments as ‘u u u u u u u u n n n n n n n n’ for a > ferromagnetic calculation and ‘u u u u d d d d n n n n n n n n’ for a > ferrimagnetic calculation. > > > Then, > > > init -b -sp -numk 500 -rkmax 8.00 > > runsp -ec 0.0001 -cc 0.0001 -fc 1.0 -p -i 200 > > > I am at a loss as to what is going on and can’t find anything in the > mailing list to explain this. Any help on this matter would be greatly > appreciated. > > > Regards, > > > Charlie > > _______________________________________________ > Wien mailing list > [email protected] > > https://urldefense.proofpoint.com/v2/url?u=http-3A__zeus.theochem.tuwien.ac.at_mailman_listinfo_wien&d=DwIF-g&c=yHlS04HhBraes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818jnvqKFdqWLwmqg0&m=67AVCnoLm7SPw-Ve2jCL6O7AZBFCNcLhTUFNw_dPuS0&s=4P8zji_3Bsaz5VC5k3QGIsLGO0L8U_c_fWRmGPdrt-U&e= > SEARCH the MAILING-LIST at: > https://urldefense.proofpoint.com/v2/url?u=http-3A__www.mail-2Darchive.com_wien-40zeus.theochem.tuwien.ac.at_index.html&d=DwIF-g&c=yHlS04HhBraes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818jnvqKFdqWLwmqg0&m=67AVCnoLm7SPw-Ve2jCL6O7AZBFCNcLhTUFNw_dPuS0&s=1fBJRUzGxLUo3u00OikWQUjgucDu9KeAABZY09-7_Ic&e= >
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