Re: [Wien] different MLD for bcc structure for magnetic equivalent directions M001, M010 and M100
Hi Gerhard, I know that due to SO, the electronic structure calculated for 100, 010 and 001 magnetization directions are different. The problem I have is following: I have three calculated electronic structures of bcc Fe, with magnetizations along 001, 010 and 100. Then, for any cubic structure, the permittivity tensor elements (ep_ij) with the same relations with respect to the magnetization should be equal in all three calculated structures. For example, symmetry clearly states that diagonal permittivity elements parallel to magnetization direction must equal ep_xx (for M=100) = ep_yy (for M=010) = ep_zz (for M=001). My problem is, that for calculated bcc Fe they do not equal. More specifically, they do not equal solely for bcc structures in wien2k, with disagreement upto 1%. For simple cubic and fcc structures they do equal, with tiny disagreement upto 0.01% Any help how to overcome this would be very helpful Thank you and with my best regards Jaroslav On 25/11/17 14:13, Fecher, Gerhard wrote: Hi Jaroslav, with SO, 001 is not equivalent to 001 or 010, if the magnetisation is along 001 this you see easily from the changed symmetry after initializing SO (symmetso) regards from Dresden 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 Jaroslav Hamrle [ham...@karlov.mff.cuni.cz] Gesendet: Freitag, 24. November 2017 16:36 An: wien@zeus.theochem.tuwien.ac.at Betreff: [Wien] different MLD for bcc structure for magnetic equivalent directions M001, M010 and M100 Dear colleagues, We have found non-physical asymmetry related with equivalent magnetization directions, when calculating electronic structure for bcc Fe: We want to calculate magnetic linear dichroism, MLD, defined as a difference between diagonal permittivity element being parallel, perpendicular to direction of magnetization, respectively. MLD=epzz - (epxx+epyy)/2 for M001 MLD=epyy - (epxx+epzz)/2 for M010 MLD=epxx - (epyy+epzz)/2 for M100 Obviously, MLD calculated for different equivalent magnetization directions should be identical. But they are not, MLD calculated for 001 is different to MLD calculated for 010 and 100 (MLD for 010 and 100 are identical). In most cases, we used k-mesh 30x30x30, exgange LDA (choice 5), with convergence criteria runsp_lapw -so -cc 0.01 -ec 0.001 -s lapw1 and the convergence was reached. * We tested this asymmetry also for fcc structures (Ni, Co, Co2MnSi). We also tested simple cubic structure (bcc Fe, defined as a simple cubic structure with two Fe atoms). In all those cases, the asymmetry disappears. On the other hand, it also appeared also in bcc Ni. Hence, the asymmetry seems to be specifically related with bcc structure. * this asymmetry can be observed already in energy levels (files case.energysoup). Hence, we think, the asymmetry is not a feature of optics. Namely, there is a very good agreement for energies for M010 and M100 (in example below difference is below 2e-7Ry), but much bigger difference between energies for M001 and (M010,M100) (in example below max. difference is 18e-6 Ry for band 5). Therefore it seems that this problem arises in either lapw0 or lapw1 for bcc structure. To demonstrate the difference, we show energy levels for the first k-point (in vicinity of the Gamma point shifted in 111 direction from the Gamma point): Fe30M001: 0.E-01 0.E-01 0.E-01 155 18 8.0 1 -3.4390104377017581 2 -3.4064979309023942 3 -3.3508627657180750 4 -3.2276472567243979 5 -3.1955089683446780 6 -3.1702455400854954 7 -7.1658179115217727E-002 8 -4.3723732810772589E-002 9 0.37296762299903474 10 0.37521967189559313 Fe30M010: 0.E-01 0.E-01 0.E-01 155 18 8.0 1 -3.4390110394480322 2 -3.4064968725403300 3 -3.3508644682352022 4 -3.2276486274720977 5 -3.1954902103327028 6 -3.1702472318057655 7 -7.1659013996950252E-002 8 -4.3723316415832839E-002 9 0.37296632778787425 10 0.37521816821120640 Fe30M100: 0.E-01 0.E-01 0.E-01 155 18 8.0 1 -3.4390109925234049 2 -3.4064968346346225 3 -3.3508643700301919 4 -3.2276485335559135 5 -3.1954901707639891
Re: [Wien] different MLD for bcc structure for magnetic equivalent directions M001, M010 and M100
There was a recent discussion on magnetic anisotropy, With a remark by Peter, Did you use a Gamma centered k mesh (and enough k points) 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 Jaroslav Hamrle [ham...@karlov.mff.cuni.cz] Gesendet: Sonntag, 26. November 2017 12:12 An: wien@zeus.theochem.tuwien.ac.at Betreff: Re: [Wien] different MLD for bcc structure for magnetic equivalent directions M001, M010 and M100 Hi Gerhard, I know that due to SO, the electronic structure calculated for 100, 010 and 001 magnetization directions are different. The problem I have is following: I have three calculated electronic structures of bcc Fe, with magnetizations along 001, 010 and 100. Then, for any cubic structure, the permittivity tensor elements (ep_ij) with the same relations with respect to the magnetization should be equal in all three calculated structures. For example, symmetry clearly states that diagonal permittivity elements parallel to magnetization direction must equal ep_xx (for M=100) = ep_yy (for M=010) = ep_zz (for M=001). My problem is, that for calculated bcc Fe they do not equal. More specifically, they do not equal solely for bcc structures in wien2k, with disagreement upto 1%. For simple cubic and fcc structures they do equal, with tiny disagreement upto 0.01% Any help how to overcome this would be very helpful Thank you and with my best regards Jaroslav On 25/11/17 14:13, Fecher, Gerhard wrote: > Hi Jaroslav, > > with SO, 001 is not equivalent to 001 or 010, if the magnetisation is along > 001 > this you see easily from the changed symmetry after initializing SO (symmetso) > > regards from Dresden > > 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 Jaroslav > Hamrle [ham...@karlov.mff.cuni.cz] > Gesendet: Freitag, 24. November 2017 16:36 > An: wien@zeus.theochem.tuwien.ac.at > Betreff: [Wien] different MLD for bcc structure for magnetic equivalent > directions M001, M010 and M100 > > Dear colleagues, > > > We have found non-physical asymmetry related with equivalent magnetization > directions, when calculating electronic structure for bcc Fe: > > We want to calculate magnetic linear dichroism, MLD, defined as a > difference between diagonal permittivity element being parallel, > perpendicular to direction of magnetization, respectively. > > MLD=epzz - (epxx+epyy)/2 for M001 > > MLD=epyy - (epxx+epzz)/2 for M010 > > MLD=epxx - (epyy+epzz)/2 for M100 > > > Obviously, MLD calculated for different equivalent magnetization > directions should > be identical. But they are not, MLD calculated for 001 is different to > MLD calculated for 010 and 100 (MLD for 010 and 100 are identical). > > In most cases, we used k-mesh 30x30x30, exgange LDA (choice 5), with > convergence criteria > > runsp_lapw -so -cc 0.01 -ec 0.001 -s lapw1 > > and the convergence was reached. > > * We tested this asymmetry also for fcc structures (Ni, Co, Co2MnSi). We > also > tested simple cubic structure (bcc Fe, defined as a simple cubic > structure with two Fe atoms). In all those cases, the asymmetry > disappears. On the other hand, it also appeared also in bcc Ni. > Hence, the asymmetry seems to be specifically related with > bcc structure. > > * this asymmetry can be observed already in energy levels (files > case.energysoup). Hence, we think, the asymmetry is not a feature of > optics. > Namely, there is a very good agreement for energies for M010 and M100 > (in example below difference is below 2e-7Ry), but much bigger > difference between energies for M001 and (M010,M100) (in example below > max. difference is 18e-6 Ry for band 5). Therefore it seems > that this problem arises in either lapw0 or lapw1 for bcc structure. > > To demonstrate the difference, we show energy levels for the first > k-point (in vicinity of the Gamma point shifted in 111 direction from > the Gamma point): > > Fe30M001: > >0.E-01 0.E-01 0.E-01 155 > 18 8.0 > 1 -3.4390104377017581 > 2 -3.4064979309023942 >
Re: [Wien] different MLD for bcc structure for magnetic equivalent directions M001, M010 and M100
I suppose that this does not have to do (much) with centering the mesh. My guess based on other QMO calculations is that some contributions to mat. els. of e.g. vx*vx from different parts of the BZ don't cancel (numerically) even if they actually should. It is instructive to repeat the calculation without SO and see how big the difference between sig_xx and sig_yy (for any M direction) is then. Cheers, Karel --- x --- dr. Karel Vyborny Fyzikalni ustav AV CR, v.v.i. Cukrovarnicka 10 Praha 6, CZ-16253 tel: +420220318459 On Sun, 26 Nov 2017, Fecher, Gerhard wrote: There was a recent discussion on magnetic anisotropy, With a remark by Peter, Did you use a Gamma centered k mesh (and enough k points) 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 Jaroslav Hamrle [ham...@karlov.mff.cuni.cz] Gesendet: Sonntag, 26. November 2017 12:12 An: wien@zeus.theochem.tuwien.ac.at Betreff: Re: [Wien] different MLD for bcc structure for magnetic equivalent directions M001, M010 and M100 Hi Gerhard, I know that due to SO, the electronic structure calculated for 100, 010 and 001 magnetization directions are different. The problem I have is following: I have three calculated electronic structures of bcc Fe, with magnetizations along 001, 010 and 100. Then, for any cubic structure, the permittivity tensor elements (ep_ij) with the same relations with respect to the magnetization should be equal in all three calculated structures. For example, symmetry clearly states that diagonal permittivity elements parallel to magnetization direction must equal ep_xx (for M=100) = ep_yy (for M=010) = ep_zz (for M=001). My problem is, that for calculated bcc Fe they do not equal. More specifically, they do not equal solely for bcc structures in wien2k, with disagreement upto 1%. For simple cubic and fcc structures they do equal, with tiny disagreement upto 0.01% Any help how to overcome this would be very helpful Thank you and with my best regards Jaroslav On 25/11/17 14:13, Fecher, Gerhard wrote: Hi Jaroslav, with SO, 001 is not equivalent to 001 or 010, if the magnetisation is along 001 this you see easily from the changed symmetry after initializing SO (symmetso) regards from Dresden 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 Jaroslav Hamrle [ham...@karlov.mff.cuni.cz] Gesendet: Freitag, 24. November 2017 16:36 An: wien@zeus.theochem.tuwien.ac.at Betreff: [Wien] different MLD for bcc structure for magnetic equivalent directions M001, M010 and M100 Dear colleagues, We have found non-physical asymmetry related with equivalent magnetization directions, when calculating electronic structure for bcc Fe: We want to calculate magnetic linear dichroism, MLD, defined as a difference between diagonal permittivity element being parallel, perpendicular to direction of magnetization, respectively. MLD=epzz - (epxx+epyy)/2 for M001 MLD=epyy - (epxx+epzz)/2 for M010 MLD=epxx - (epyy+epzz)/2 for M100 Obviously, MLD calculated for different equivalent magnetization directions should be identical. But they are not, MLD calculated for 001 is different to MLD calculated for 010 and 100 (MLD for 010 and 100 are identical). In most cases, we used k-mesh 30x30x30, exgange LDA (choice 5), with convergence criteria runsp_lapw -so -cc 0.01 -ec 0.001 -s lapw1 and the convergence was reached. * We tested this asymmetry also for fcc structures (Ni, Co, Co2MnSi). We also tested simple cubic structure (bcc Fe, defined as a simple cubic structure with two Fe atoms). In all those cases, the asymmetry disappears. On the other hand, it also appeared also in bcc Ni. Hence, the asymmetry seems to be specifically related with bcc structure. * this asymmetry can be observed already in energy levels (files case.energysoup). Hence, we think, the asymmetry is not a feature of optics. Namely, there is a very good agreement for energies for M010 and M100 (in example below difference is below 2e-7Ry), but much bigger difference between energies for M001 and (M010,M100) (in example below max. difference is