Re: [Wien] AFM type II
Dear Gerhard, nice ... thanks a lot for the references! Best regards, Martin --- Dr. Martin Pieper Karl-Franzens University Institute of Physics Universitätsplatz 5 A-8010 Graz Austria Tel.: +43-(0)316-380-8564 Am 2020-01-29 13:16, schrieb Fecher, Gerhard: Dear Martin, this concerns your remark: "With two magnetic species, say, Mn and Cu, you would wind up with different size of the moment on Mn and Cu. I know of no case where exact compensation into an AFM structure occures by accident in such a situation." You may have the situation of a completely compensated ferrimagnet exampels are: CrMnSb (or VFeSb) in the cubic C1b structure H. van Leuken and R. A. de Groot, Phys. Rev. Lett. 74, 1171 (1995) or more complicated Mn1.5FeV0.5Al Rolf Stinshoff et al; Phys. Rev. B 95, 060410(R) (2017) However, it is by purpose rather than by accident. This was already found by Neel in his work on antiferromagnets (probably it is mentioned in the Nobel lecture) 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 [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von pieper [pie...@ifp.tuwien.ac.at] Gesendet: Mittwoch, 29. Januar 2020 12:49 An: A Mailing list for WIEN2k users Betreff: Re: [Wien] AFM type II No one can give you an honest answer without knowing the structure you put these elements in. Zr, S, Se are almost certainely non-magnetic, but there are quite a few structures with magnetic moments on Cr, Cu, and of course on Mn. To make terminology more complicated, remember that AFM means fully compensated magnetic moments. The net magnetization of a unit cell of some AFM structure is zero. This does not happen by coincidence, it is because by symmetry all moments have the same size, and there are as many of them pointing in one direction as there are pointing in exactly the opposite direction. So, IF your compound REALLY is AFM by experiment (NO net magnetization), you almost certainely have only one magnetic species in there (probably Mn). With two magnetic species, say, Mn and Cu, you would wind up with different size of the moment on Mn and Cu. I know of no case where exact compensation into an AFM structure occures by accident in such a situation. You always get something with net moment - and these are called ferrimagnetic structures. And since we are at it: there are canted and helical strucutures where the moments are not collinear (not within the scope of Wien2k), there are spin density waves, ... Scanning this thread my advice would be to study a (good) book on solid state physics, with special attention payed to its chapter discussing magnetic order. If it doesn't have such a chapter its not a good book - at least not for you. Do NOT use wikipedia or this mailing list and its archive as a substitute for such a reading. It will not work. --- Dr. Martin Pieper Karl-Franzens University Institute of Physics Universitätsplatz 5 A-8010 Graz Austria Tel.: +43-(0)316-380-8564 Am 2020-01-27 17:45, schrieb djamel slamnia: WHEN I STUDY A COMPOUND CONTAINS THIS ELEMENETS CU MN CR ZR S SE BETWEEN THEM WITCH ONE TO PUT IT SPIN UP OR DOWN AND NON-MAGNETIC ??? Le lundi 27 janvier 2020 à 14:22:39 UTC+1, Gavin Abo a écrit : As previously mentioned [1], a short literature survey showed that AFM type II and III are terms used for _fcc_ and _bcc_ lattices. Since spacegroup 156 is not one of those, it might be inappropriate to use those terms for spacegroup 156 having a _primitive_ lattice [2] of the hexagonal crystal family. If you do a more extensive literature survey yourself and find a paper (article, book, etc.) that defines the AFM magnetic orders for spacegroup 156, then reference and use it for what the AFM order is. If there is not any notations and terms for AFM magnetic orders for spacegroup 156, you might have to make your own figure or write in your own words what the definition is should any AFM magnetic orders exist for it. Keep in mind that as mentioned before in the mailing list archive, the initial configuration can be set in case.inst with "instgen_lapw -ask" [3]. Though, you need to check the final magnetic order that comes out of the scf [4], because the configuration set in case.inst with instgen_lapw is just the initial one that could change [5,6]. It is also possible to try to force a magnetic order using dmatup/dn matrices but the final magnetic order is still what comes out of the scf and could be different [6-11]. Therefore, it likely not beneficial to name the AFM order before starting a calculation such that you wou
Re: [Wien] AFM type II
Dear Martin, this concerns your remark: "With two magnetic species, say, Mn and Cu, you would wind up with different size of the moment on Mn and Cu. I know of no case where exact compensation into an AFM structure occures by accident in such a situation." You may have the situation of a completely compensated ferrimagnet exampels are: CrMnSb (or VFeSb) in the cubic C1b structure H. van Leuken and R. A. de Groot, Phys. Rev. Lett. 74, 1171 (1995) or more complicated Mn1.5FeV0.5Al Rolf Stinshoff et al; Phys. Rev. B 95, 060410(R) (2017) However, it is by purpose rather than by accident. This was already found by Neel in his work on antiferromagnets (probably it is mentioned in the Nobel lecture) 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 [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von pieper [pie...@ifp.tuwien.ac.at] Gesendet: Mittwoch, 29. Januar 2020 12:49 An: A Mailing list for WIEN2k users Betreff: Re: [Wien] AFM type II No one can give you an honest answer without knowing the structure you put these elements in. Zr, S, Se are almost certainely non-magnetic, but there are quite a few structures with magnetic moments on Cr, Cu, and of course on Mn. To make terminology more complicated, remember that AFM means fully compensated magnetic moments. The net magnetization of a unit cell of some AFM structure is zero. This does not happen by coincidence, it is because by symmetry all moments have the same size, and there are as many of them pointing in one direction as there are pointing in exactly the opposite direction. So, IF your compound REALLY is AFM by experiment (NO net magnetization), you almost certainely have only one magnetic species in there (probably Mn). With two magnetic species, say, Mn and Cu, you would wind up with different size of the moment on Mn and Cu. I know of no case where exact compensation into an AFM structure occures by accident in such a situation. You always get something with net moment - and these are called ferrimagnetic structures. And since we are at it: there are canted and helical strucutures where the moments are not collinear (not within the scope of Wien2k), there are spin density waves, ... Scanning this thread my advice would be to study a (good) book on solid state physics, with special attention payed to its chapter discussing magnetic order. If it doesn't have such a chapter its not a good book - at least not for you. Do NOT use wikipedia or this mailing list and its archive as a substitute for such a reading. It will not work. --- Dr. Martin Pieper Karl-Franzens University Institute of Physics Universitätsplatz 5 A-8010 Graz Austria Tel.: +43-(0)316-380-8564 Am 2020-01-27 17:45, schrieb djamel slamnia: > WHEN I STUDY A COMPOUND CONTAINS THIS ELEMENETS CU MN CR ZR S SE > > BETWEEN THEM WITCH ONE TO PUT IT SPIN UP OR DOWN AND NON-MAGNETIC ??? > > Le lundi 27 janvier 2020 à 14:22:39 UTC+1, Gavin Abo > a écrit : > > As previously mentioned [1], a short literature survey showed that > AFM type II and III are terms used for _fcc_ and _bcc_ lattices. > Since spacegroup 156 is not one of those, it might be inappropriate to > use those terms for spacegroup 156 having a _primitive_ lattice [2] of > the hexagonal crystal family. If you do a more extensive literature > survey yourself and find a paper (article, book, etc.) that defines > the AFM magnetic orders for spacegroup 156, then reference and use it > for what the AFM order is. If there is not any notations and terms > for AFM magnetic orders for spacegroup 156, you might have to make > your own figure or write in your own words what the definition is > should any AFM magnetic orders exist for it. > Keep in mind that as mentioned before in the mailing list archive, the > initial configuration can be set in case.inst with "instgen_lapw -ask" > [3]. > > Though, you need to check the final magnetic order that comes out of > the scf [4], because the configuration set in case.inst with > instgen_lapw is just the initial one that could change [5,6]. > > It is also possible to try to force a magnetic order using dmatup/dn > matrices but the final magnetic order is still what comes out of the > scf and could be different [6-11]. > > Therefore, it likely not beneficial to name the AFM order before > starting a calculation such that you would likely want to identify the > name of the magnetic order after having finished the converged > calculation.
Re: [Wien] AFM type II
No one can give you an honest answer without knowing the structure you put these elements in. Zr, S, Se are almost certainely non-magnetic, but there are quite a few structures with magnetic moments on Cr, Cu, and of course on Mn. To make terminology more complicated, remember that AFM means fully compensated magnetic moments. The net magnetization of a unit cell of some AFM structure is zero. This does not happen by coincidence, it is because by symmetry all moments have the same size, and there are as many of them pointing in one direction as there are pointing in exactly the opposite direction. So, IF your compound REALLY is AFM by experiment (NO net magnetization), you almost certainely have only one magnetic species in there (probably Mn). With two magnetic species, say, Mn and Cu, you would wind up with different size of the moment on Mn and Cu. I know of no case where exact compensation into an AFM structure occures by accident in such a situation. You always get something with net moment - and these are called ferrimagnetic structures. And since we are at it: there are canted and helical strucutures where the moments are not collinear (not within the scope of Wien2k), there are spin density waves, ... Scanning this thread my advice would be to study a (good) book on solid state physics, with special attention payed to its chapter discussing magnetic order. If it doesn't have such a chapter its not a good book - at least not for you. Do NOT use wikipedia or this mailing list and its archive as a substitute for such a reading. It will not work. --- Dr. Martin Pieper Karl-Franzens University Institute of Physics Universitätsplatz 5 A-8010 Graz Austria Tel.: +43-(0)316-380-8564 Am 2020-01-27 17:45, schrieb djamel slamnia: WHEN I STUDY A COMPOUND CONTAINS THIS ELEMENETS CU MN CR ZR S SE BETWEEN THEM WITCH ONE TO PUT IT SPIN UP OR DOWN AND NON-MAGNETIC ??? Le lundi 27 janvier 2020 à 14:22:39 UTC+1, Gavin Abo a écrit : As previously mentioned [1], a short literature survey showed that AFM type II and III are terms used for _fcc_ and _bcc_ lattices. Since spacegroup 156 is not one of those, it might be inappropriate to use those terms for spacegroup 156 having a _primitive_ lattice [2] of the hexagonal crystal family. If you do a more extensive literature survey yourself and find a paper (article, book, etc.) that defines the AFM magnetic orders for spacegroup 156, then reference and use it for what the AFM order is. If there is not any notations and terms for AFM magnetic orders for spacegroup 156, you might have to make your own figure or write in your own words what the definition is should any AFM magnetic orders exist for it. Keep in mind that as mentioned before in the mailing list archive, the initial configuration can be set in case.inst with "instgen_lapw -ask" [3]. Though, you need to check the final magnetic order that comes out of the scf [4], because the configuration set in case.inst with instgen_lapw is just the initial one that could change [5,6]. It is also possible to try to force a magnetic order using dmatup/dn matrices but the final magnetic order is still what comes out of the scf and could be different [6-11]. Therefore, it likely not beneficial to name the AFM order before starting a calculation such that you would likely want to identify the name of the magnetic order after having finished the converged calculation. [1] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg19515.html [2] https://en.wikipedia.org/wiki/Crystal_structure#Lattice_systems [3] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10044.html [4] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17516.html [5] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg03243.html [6] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg06739.html [7] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14259.html [8] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg05054.html [9] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg13124.html [10] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg16281.html [11] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg16286.html On 1/26/2020 1:01 PM, djamel slamnia wrote: THANKS AGAIN SIR I NEED TO KNOW WHAT IS THE AFM ORDERS FOR P3M1 (156) ??? TYPE II OR III THANKS IN ADVANCE ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] AFM type II
when i study a compound contains this elemenets Cu Mn Cr Zr S Se between them witch one to put it spin up or down and non-magnetic ??? Le lundi 27 janvier 2020 à 14:22:39 UTC+1, Gavin Abo a écrit : As previously mentioned [1], a short literature survey showed that AFM type II and III are terms used for fcc and bcc lattices. Since spacegroup 156 is not one of those, it might be inappropriate to use those terms for spacegroup 156 having a primitive lattice [2] of the hexagonal crystal family. If you do a more extensive literature survey yourself and find a paper (article, book, etc.) that defines the AFM magnetic orders for spacegroup 156, then reference and use it for what the AFM order is. If there is not any notations and terms for AFM magnetic orders for spacegroup 156, you might have to make your own figure or write in your own words what the definition is should any AFM magnetic orders exist for it. Keep in mind that as mentioned before in the mailing list archive, the initial configuration can be set in case.inst with "instgen_lapw -ask" [3]. Though, you need to check the final magnetic order that comes out of the scf [4], because the configuration set in case.inst with instgen_lapw is just the initial one that could change [5,6]. It is also possible to try to force a magnetic order using dmatup/dn matrices but the final magnetic order is still what comes out of the scf and could be different [6-11]. Therefore, it likely not beneficial to name the AFM order before starting a calculation such that you would likely want to identify the name of the magnetic order after having finished the converged calculation. [1]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg19515.html [2] https://en.wikipedia.org/wiki/Crystal_structure#Lattice_systems [3]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10044.html [4]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17516.html [5]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg03243.html [6]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg06739.html [7]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14259.html [8]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg05054.html [9]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg13124.html [10]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg16281.html [11]https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg16286.html On 1/26/2020 1:01 PM, djamel slamnia wrote: thanks again sir i need to know what is the AFM orders for P3m1 (156) ??? type II or III thanks in advance ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] AFM type II
As previously mentioned [1], a short literature survey showed that AFM type II and III are terms used for /fcc/ and /bcc/ lattices. Since spacegroup 156 is not one of those, it might be inappropriate to use those terms for spacegroup 156 having a /primitive/ lattice [2] of the hexagonal crystal family. If you do a more extensive literature survey yourself and find a paper (article, book, etc.) that defines the AFM magnetic orders for spacegroup 156, then reference and use it for what the AFM order is. If there is not any notations and terms for AFM magnetic orders for spacegroup 156, you might have to make your own figure or write in your own words what the definition is should any AFM magnetic orders exist for it. Keep in mind that as mentioned before in the mailing list archive, the initial configuration can be set in case.inst with "instgen_lapw -ask" [3]. Though, you need to check the final magnetic order that comes out of the scf [4], because the configuration set in case.inst with instgen_lapw is just the initial one that could change [5,6]. It is also possible to try to force a magnetic order using dmatup/dn matrices but the final magnetic order is still what comes out of the scf and could be different [6-11]. Therefore, it likely not beneficial to name the AFM order before starting a calculation such that you would likely want to identify the name of the magnetic order after having finished the converged calculation. [1] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg19515.html [2] https://en.wikipedia.org/wiki/Crystal_structure#Lattice_systems [3] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10044.html [4] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17516.html [5] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg03243.html [6] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg06739.html [7] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14259.html [8] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg05054.html [9] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg13124.html [10] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg16281.html [11] https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg16286.html On 1/26/2020 1:01 PM, djamel slamnia wrote: *thanks again sir * * * *i need to know what is the AFM orders for P3m1 (156) ??? type II or III * ** ** *thanks in advance* ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] AFM type II
I guess you are talking about the conventional classification of AFM ordering used in neutron diffraction. Consider AFM as a standing wave of spin orientations. Different Types of AFM are then distinguished by the wave vector of the standing wave in the crystal lattice. AFM-I is the AFM order with the shortest possible wavelength, that is moments on nearest neighbor planes are antiparallel. In an fcc structure the nearest neighbors of an atom at (0,0,0) are on the two planes 'above' and 'below' along the space diagonal of the cube at positions (1/2,1/2,0) and so on. The wave vector of the standing wave describing spin orientation is perpendicular to these planes of parallel spins. The length of the wave vector q in reciprocal space is such that going the distance d to the next plane with parallel moments (half the space diagonal) in that direction result in an identical situation in the wave function cos(qx), that is q*d=2*pi. For AFM-II moments on planes with next nearest neighbors are antiparallel. And so on. The longer the wavelength of the standing wave (or the shorter q in reciprocal space) the more unit cells in the crystal lattice you will need to represent the AFM structure (depending on the distance between lattice planes in your structure without AFM order). Good luck with figuring out the directions and lengths of wave vectors in your structure yourself, Martin Pieper --- Dr. Martin Pieper Karl-Franzens University Institute of Physics Universitätsplatz 5 A-8010 Graz Austria Tel.: +43-(0)316-380-8564 Am 2020-01-26 21:01, schrieb djamel slamnia: THANKS AGAIN SIR I NEED TO KNOW WHAT IS THE AFM ORDERS FOR P3M1 (156) ??? TYPE II OR III THANKS IN ADVANCE Le dimanche 26 janvier 2020 à 20:51:41 UTC+1, Gavin Abo a écrit : THE DEFINITION FOR THE COMPOUND A=B = 3.74 A ALPHA = BETA = 90 GAMMA = 120 for AFM type I : i creat superstructure x super cell target lattice H : x =1, y = 1 , Z =2 then x sgroup, program define automatically the space group the same of my original space group 156 without warrning As you have described above (for Z=2), your attempt at creating a supercell has failed as "x sgroup" collapsed the supercell structure back to the non-supercell structure. As mentioned on the FAQ page for supercell construction, you need to displace an atom, change an atom, or use a special label: http://susi.theochem.tuwien.ac.at/reg_user/faq/supercells.html In order to keep the supercell without "x sgroup" reducing it back to the original structure, refer to previous posts in the mailing list archive about breaking the symmetry. A few of the many posts about that as examples are at the three links below: https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18380.html https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg01866.html https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15517.html but when try to do it for type II : x super cell P : x =1, y = 1 , Z =1 x sgroup could not define the space group In section "3.12 Setting up a new case" on page 29 in the WIEN2k 19.1 usersguide [ http://susi.theochem.tuwien.ac.at/reg_user/textbooks/usersguide.pdf ], there is the statement: "Alternatively with the new StructGen you can specify the spacegroup and only the inequivalent positions. The equivalent ones will be generated automatically." This means spacegroups in WIEN2k are defined according to the inequivalent positions and not by the equivalent positions. For the case above (Z=1), it is likely that "x supercell" found some equivalent positions in the original structure and automatically added special labels to them changing them into inequivalent positions. Thus, a supercell structure was successfully created. If you want the supercell structure to reduce back to the original structure, you would likely just need to remove all or some of the special labels in StructGen before running "x sgroup". For understanding the inequivalent and equivalent positions with WIEN2k spacegroups, the example in the post at the following link might helpful: http://zeus.theochem.tuwien.ac.at/pipermail/wien/2013-January/018171.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] AFM type II
thanks again sir i need to know what is the AFM orders for P3m1 (156) ??? type II or III thanks in advance Le dimanche 26 janvier 2020 à 20:51:41 UTC+1, Gavin Abo a écrit : the definition for the compound a=b = 3.74 A alpha = beta = 90 gamma = 120 for AFM type I : i creat superstructure x super cell target lattice H : x =1, y = 1 , Z =2 then x sgroup, program define automatically the space group the same of my original space group 156 without warrning As you have described above (for Z=2), your attempt at creating a supercell has failed as "x sgroup" collapsed the supercell structure back to the non-supercell structure. As mentioned on the FAQ page for supercell construction, you need to displace an atom, change an atom, or use a special label: http://susi.theochem.tuwien.ac.at/reg_user/faq/supercells.html In order to keep the supercell without "x sgroup" reducing it back to the original structure, refer to previous posts in the mailing list archive about breaking the symmetry. A few of the many posts about that as examples are at the three links below: https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18380.html https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg01866.html https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15517.html but when try to do it for type II : x super cell P : x =1, y = 1 , Z =1 x sgroup could not define the space group In section "3.12 Setting up a new case" on page 29 in the WIEN2k 19.1 usersguide [ http://susi.theochem.tuwien.ac.at/reg_user/textbooks/usersguide.pdf ], there is the statement: "Alternatively with the new StructGen you can specify the spacegroup and only the inequivalent positions. The equivalent ones will be generated automatically." This means spacegroups in WIEN2k are defined according to the inequivalent positions and not by the equivalent positions. For the case above (Z=1), it is likely that "x supercell" found some equivalent positions in the original structure and automatically added special labels to them changing them into inequivalent positions. Thus, a supercell structure was successfully created. If you want the supercell structure to reduce back to the original structure, you would likely just need to remove all or some of the special labels in StructGen before running "x sgroup". For understanding the inequivalent and equivalent positions with WIEN2k spacegroups, the example in the post at the following link might helpful: http://zeus.theochem.tuwien.ac.at/pipermail/wien/2013-January/018171.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] AFM type II
* the definition for the compound a=b = 3.74 A alpha = beta = 90 gamma = 120 * *for AFM type I : i creat superstructure x super cell target lattice H : x =1, y = 1 , Z =2 then x sgroup, program define automatically the space group the same of my original space group 156 without warrning * As you have described above (for Z=2), your attempt at creating a supercell has failed as "x sgroup" collapsed the supercell structure back to the non-supercell structure. As mentioned on the FAQ page for supercell construction, you need to displace an atom, change an atom, or use a special label: http://susi.theochem.tuwien.ac.at/reg_user/faq/supercells.html In order to keep the supercell without "x sgroup" reducing it back to the original structure, refer to previous posts in the mailing list archive about breaking the symmetry. A few of the many posts about that as examples are at the three links below: https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18380.html https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg01866.html https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15517.html *but when try to do it for type II : x super cell P : x =1, y = 1 , Z =1 x sgroup could not define the space group * In section "3.12 Setting up a new case" on page 29 in the WIEN2k 19.1 usersguide [ http://susi.theochem.tuwien.ac.at/reg_user/textbooks/usersguide.pdf ], there is the statement: "Alternatively with the new StructGen you can specify the spacegroup and only the inequivalent positions. The equivalent ones will be generated automatically." This means spacegroups in WIEN2k are defined according to the inequivalent positions and not by the equivalent positions. For the case above (Z=1), it is likely that "x supercell" found some equivalent positions in the original structure and automatically added special labels to them changing them into inequivalent positions. Thus, a supercell structure was successfully created. If you want the supercell structure to reduce back to the original structure, you would likely just need to remove all or some of the special labels in StructGen before running "x sgroup". For understanding the inequivalent and equivalent positions with WIEN2k spacegroups, the example in the post at the following link might helpful: http://zeus.theochem.tuwien.ac.at/pipermail/wien/2013-January/018171.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] AFM type II
thanks you sir the definition for the compound a=b = 3.74 A alpha = beta = 90 gamma = 120 for AFM type I : i creat superstructure x super cell target lattice H : x =1, y = 1 , Z =2 then x sgroup, program define automatecly the space group the same of my original space group 156 without warrning but when try to do it for type II : x super cell P : x =1, y = 1 , Z =1 x sgroup could not define the space group i dont know why ??? Le dimanche 26 janvier 2020 à 07:33:30 UTC+1, Gavin Abo a écrit : Space group 156 is part of the hexagonal crystal family [1]. It seems that AFM type I, II, and/or III typically are only defined for body centered cubic (bcc) and face centered cubic (fcc) lattices. That is based on books such as "Magnetism and Magnetic Materials" by J. M. D. Coey (Figure 6.9 and 6.10) [2] and Quantum Theory of Magnetism by R. M. White (Fig. 4.2) [3] defining AFM type I, II, and/or III for bcc and fcc lattices. The bcc and fcc lattices are listed under the 14 Bravais Lattices in the table at [4]. The article titled "Ferromagnetic and antiferromagnetic spin fluctuations and superconductivity in the hcp-phase of Fe" [5] defines AFM type II as having opposite polarization on each layer perpendicular to the x-axis. The article titled "Electronic origins of the magnetic phase transitions in zinc-blende Mn chalcogenides" [6] defines AFM type II as a super-lattice of period p = 1 and layer orientation G = (111). Since there seems to be varying definitions for the AFM types, it is unknown what your AFM type II and III are as you did not provide the definition for it using words or images like in those books and articles. [1] https://en.wikipedia.org/wiki/Hexagonal_crystal_family [2] https://doi.org/10.1017/CBO9780511845000 [3] https://www.springer.com/gp/book/9783540651161 [4] https://en.wikipedia.org/wiki/Crystal_structure#Lattice_systems [5] https://arxiv.org/abs/cond-mat/0112382v1 [6] https://doi.org/10.1103/PhysRevB.48.6111 On 1/25/2020 4:41 AM, djamel slamnia wrote: dear wien2k user's I got big problem to creat a structure for AFM type II or type III Compound : H LATTICE,NONEQUIV.ATOMS: 5 156_P3m1 4 atoms ?? any solution ??? thanks in advance ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] AFM type II
Space group 156 is part of the hexagonal crystal family [1]. It seems that AFM type I, II, and/or III typically are only defined for body centered cubic (bcc) and face centered cubic (fcc) lattices. That is based on books such as "Magnetism and Magnetic Materials" by J. M. D. Coey (Figure 6.9 and 6.10) [2] and Quantum Theory of Magnetism by R. M. White (Fig. 4.2) [3] defining AFM type I, II, and/or III for bcc and fcc lattices. The bcc and fcc lattices are listed under the 14 Bravais Lattices in the table at [4]. The article titled "Ferromagnetic and antiferromagnetic spin fluctuations and superconductivity in the hcp-phase of Fe" [5] defines AFM type II as having opposite polarization on each layer perpendicular to the x-axis. The article titled "Electronic origins of the magnetic phase transitions in zinc-blende Mn chalcogenides" [6] defines AFM type II as a super-lattice of period /p/ = 1 and layer orientation G = (111). Since there seems to be varying definitions for the AFM types, it is unknown what your AFM type II and III are as you did not provide the definition for it using words or images like in those books and articles. [1] https://en.wikipedia.org/wiki/Hexagonal_crystal_family [2] https://doi.org/10.1017/CBO9780511845000 [3] https://www.springer.com/gp/book/9783540651161 [4] https://en.wikipedia.org/wiki/Crystal_structure#Lattice_systems [5] https://arxiv.org/abs/cond-mat/0112382v1 [6] https://doi.org/10.1103/PhysRevB.48.6111 On 1/25/2020 4:41 AM, djamel slamnia wrote: *dear wien2k user's * * * *I got big problem to creat a structure for AFM type II or type III* * * *Compound : H LATTICE,NONEQUIV.ATOMS: 5 156_P3m1 4 atoms ?? * * * * * *any solution ???* *thanks in advance * ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
[Wien] AFM type II
dear wien2k user's I got big problem to creat a structure for AFM type II or type III Compound : H LATTICE,NONEQUIV.ATOMS: 5 156_P3m1 4 atoms ?? any solution ??? thanks in advance ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
