Re: [Wien] Tb metal
Dear Drs. Marks and Blaha, Thank you very much! Your suggestions are very helpful. I spent quite some time to investigate each of your suggestions. It seems the experience on this is publishable. Yes, I am sorry that I should have said that I got different results. I indeed noticed that sentence, but unfortunately they did not specify the exact occupancy. Now I adopted (0,1,0) and also followed the steps that Dr. Blaha outlined. I also found an old email on Wien2k mailing list by Stefaan Cottenier and someone had the same trouble to computer Tb. Step 1. I did (runsp -so -p) and saved the results Step 2. x lapwdm -so -up/dn -p Step 3. ---Option 0: runsp -so -orb -p. This does not work. The orbital moment is too small. ---Option 1: I tried Steffan's idea. I delete all the elements case.dmatdn except the first element. I set that element to one since I want the single electron to occupy m=+3. Then I did run x orb -up/dn runsp -orbc -so -p -i 4 (frozen orbital potentials) Unfortunately, this does not work. case.dmatdn is changing. ---Option 2: I use my above constructed case.dmatdn and then run runsp -so -orb -p -i 4 This converged, and case.dmatdn does not change much. See --- 1 atom density matrix 3 0.00 0.105011 0.00 L, Lx,Ly,Lz in global orthogonal system 9.24539125E-01 0.E+000.E+00 -2.70811019E-03 -1.61197845E-04 0.E+000.E+00 1.50798088E-05 -4.05482624E-05 0.E+000.E+00 2.93799262E-06 5.30090286E-05 0.E+00 --- BUT, the program still gives a tiny orbital moment. I attach the case.dmatdn file so you can the entire matrix elements. While option 2 seems the best, I do not understand how the orbital moment is computed to be so small. In my case.scf, I have :ORB001: ORBITAL MOMENT: 0.0 0.10303 0.0 PROJECTION ON M 0.10303 Do you have any ideas or suggestions? Thank you very much ! Best regards, Guoping On Mon, 5 Dec 2016, Laurence Marks wrote: Why do you state that Wien2k is wrong? What you really should be saying is that you got different results. If you read that paper carefully, you will see that they state "The occupancy of the minority 4f orbitals was chosen to yield an in-plane orbital moment of almost 3??B." Did you pick the same occupancy? Did you explore the different orbital occupancy states to see which was lowest in energy? Particularly for 4f states, but others as well, there can be multiple spin/orbital states and it is easy to be trapped in one which may be higher in energy (or not). On Mon, Dec 5, 2016 at 12:10 PM, Guo-ping Zhang wrote: Dear Prof. Blaba and Wien2k developers, Thank you very much for your prior help. Recently, I was testing whether Wien2k can compute Tb metal's spin and orbital moments correctly, but unsuccessful. I follow the paper by Dobrich et al. PRB 76, 035123 (2007). The correct spin moment should be around 6 uB and orbital 3 uB, but Wien gave spin moment of 11.72562 uB/2 which is close to 6 uB (which is OK), and the orbital moment of 1.43494 uB (:ORB001), which is too small. My RKmax is 9.52. I include 4f in the valence, (case.in1: 30.30 0.005 CONT 1 ). I also checked my case.inst. It looks also fine. Tb Xe 4 4, 3,3.0 N 4, 3,1.0 N 4,-4,4.0 N 4,-4,0.0 N 5, 2,1.0 N 5, 2,0.0 N 6,-1,1.0 N 6,-1,1.0 N END of input (instgen_lapw) In case.scf the number of electrons (:NOE) is consistently 38. This is also correct. What is even strange is that the results do not change by adding +U option or not. +U results :ORB001: ORBITAL MOMENT: 0.72713 -1.25942 0.0 PROJECTION ON M 1.45428 :MMTOT: SPIN MAGNETIC MOMENT IN CELL = 11.65626 U=0 results :ORB001: ORBITAL MOMENT: 0.71746 -1.24270 0.0 PROJECTION ON M 1.43494 :MMTOT: SPIN MAGNETIC MOMENT IN CELL = 11.72562 I have attached my structure file in case you want to test it youself. I can not figure out why wien did this all incorrect. Any help is greatly appreciated. Best regards, Guoping -- Professor Laurence Marks "Research is to see what everybody else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi www.numis.northwestern.edu ; Corrosion in 4D: MURI4D.numis.northwestern.edu Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent Co-Editor, Acta Cryst A ___ 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] Tb metal
A few more comments in addition to what L.Marks said: a) In this paper they say: The magnetization is along the b-axis, i.e. (1-100). In WIEN2k we use a different convention, where the hexagonal b axis and the carth. y axis coincides (and not the a and carth. x axis). I thus believe it should be the (010) direction ! b) As mentioned before, with localized 4f (or sometimes 3d) states it is easily possible to obtain several metastable minima as solution of an unbiased scf cycle when using GGA+U. It is therefore important (but not always sufficient) to run a sequence: runsp -so and only afterwards: x lapwdm -so -up/dn runsp -so -orb If you still do not get the desired solution, you can try and manually reoccupy the 4f orbitals in case.dmatup/dn. Presumably, Tb has a full 4f spin-up shell, but only one spin-dn electron. This gives a spin moment of 6, and in order to get an orbital moment of 3, an m=3 state must be occupied in spin-dn. Presumably your spin-dn density matrix with M_orb=1.5 looks quite different. You can then also compare total energies of the different solutions .. On 12/05/2016 07:10 PM, Guo-ping Zhang wrote: Dear Prof. Blaba and Wien2k developers, Thank you very much for your prior help. Recently, I was testing whether Wien2k can compute Tb metal's spin and orbital moments correctly, but unsuccessful. I follow the paper by Dobrich et al. PRB 76, 035123 (2007). The correct spin moment should be around 6 uB and orbital 3 uB, but Wien gave spin moment of 11.72562 uB/2 which is close to 6 uB (which is OK), and the orbital moment of 1.43494 uB (:ORB001), which is too small. My RKmax is 9.52. I include 4f in the valence, (case.in1: 30.30 0.005 CONT 1 ). I also checked my case.inst. It looks also fine. Tb Xe 4 4, 3,3.0 N 4, 3,1.0 N 4,-4,4.0 N 4,-4,0.0 N 5, 2,1.0 N 5, 2,0.0 N 6,-1,1.0 N 6,-1,1.0 N END of input (instgen_lapw) In case.scf the number of electrons (:NOE) is consistently 38. This is also correct. What is even strange is that the results do not change by adding +U option or not. +U results :ORB001: ORBITAL MOMENT: 0.72713 -1.25942 0.0 PROJECTION ON M 1.45428 :MMTOT: SPIN MAGNETIC MOMENT IN CELL = 11.65626 U=0 results :ORB001: ORBITAL MOMENT: 0.71746 -1.24270 0.0 PROJECTION ON M 1.43494 :MMTOT: SPIN MAGNETIC MOMENT IN CELL = 11.72562 I have attached my structure file in case you want to test it youself. I can not figure out why wien did this all incorrect. Any help is greatly appreciated. Best regards, Guoping ___ 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 -- P.Blaha -- Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna Phone: +43-1-58801-165300 FAX: +43-1-58801-165982 Email: bl...@theochem.tuwien.ac.atWIEN2k: http://www.wien2k.at WWW: http://www.imc.tuwien.ac.at/TC_Blaha -- ___ 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] Tb metal
Why do you state that Wien2k is wrong? What you really should be saying is that you got different results. If you read that paper carefully, you will see that they state "The occupancy of the minority 4f orbitals was chosen to yield an in-plane orbital moment of almost 3μB." Did you pick the same occupancy? Did you explore the different orbital occupancy states to see which was lowest in energy? Particularly for 4f states, but others as well, there can be multiple spin/orbital states and it is easy to be trapped in one which may be higher in energy (or not). On Mon, Dec 5, 2016 at 12:10 PM, Guo-ping Zhang wrote: > Dear Prof. Blaba and Wien2k developers, > > Thank you very much for your prior help. > > Recently, I was testing whether Wien2k can compute Tb metal's spin and > orbital moments correctly, but unsuccessful. I follow the paper by > Dobrich et al. PRB 76, 035123 (2007). The correct spin moment should be > around 6 uB and orbital 3 uB, but Wien gave spin moment of 11.72562 uB/2 > which is close to 6 uB (which is OK), and the orbital moment of 1.43494 uB > (:ORB001), which is too small. My RKmax is 9.52. I include 4f in the > valence, (case.in1: 30.30 0.005 CONT 1 ). I also checked my > case.inst. It looks also fine. > Tb > Xe 4 > 4, 3,3.0 N > 4, 3,1.0 N > 4,-4,4.0 N > 4,-4,0.0 N > 5, 2,1.0 N > 5, 2,0.0 N > 6,-1,1.0 N > 6,-1,1.0 N > > END of input (instgen_lapw) > > In case.scf the number of electrons (:NOE) is consistently 38. This is > also correct. What is even strange is that the results do not change by > adding +U option or not. > > +U results > :ORB001: ORBITAL MOMENT: 0.72713 -1.25942 0.0 PROJECTION ON M > 1.45428 > :MMTOT: SPIN MAGNETIC MOMENT IN CELL = 11.65626 > > U=0 results > :ORB001: ORBITAL MOMENT: 0.71746 -1.24270 0.0 PROJECTION ON M > 1.43494 > :MMTOT: SPIN MAGNETIC MOMENT IN CELL = 11.72562 > > > I have attached my structure file in case you want to test it youself. > > I can not figure out why wien did this all incorrect. > > Any help is greatly appreciated. > > Best regards, > > Guoping > -- Professor Laurence Marks "Research is to see what everybody else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi www.numis.northwestern.edu ; Corrosion in 4D: MURI4D.numis.northwestern.edu Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent Co-Editor, Acta Cryst A ___ 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
